Sabrina's parents met in Paris, her father an older diplomat married her much younger American mother Zara, and Sabrina was born when Zara was still very young. After her Father was assassinated by a car bombing when she was 12, her Mother became frenetic, always on the go. Though they were never close, Zara thought of her as a friend, dressed her older, took her to clubs to pick up men, ordering drinks for her, and claiming they were sisters. Eventually Sabrina was sent to boarding school so Zara could be free to find another rich husband.

Best friends Sabrina Costelana and Victoria Newman met when they both attended the Guggenheim Program in Florence, Italy. Sabrina was getting her Masters in Art History and Victoria was an undergrad student. They met again and were roommates in Paris where Sabrina was the Art Curator at the Pompidou museum. Victoria eventually returned to Genoa City, but she and Sabrina would meet up again in Florence years later when Victoria left Newman Enterprises. This time around, Sabrina was working with private collectors procuring artwork and Victoria was teaching art at a convent school.

In 2008, with plans of making a new beginning in New York City as a Consulting Private Curator, Sabrina stopped in Genoa City to check in on Victoria, who had just come out of a months-long coma. Sabrina had just broken up with her lover, Phillipe, a talented artist she placed in an art show only to have him dump her afterward. Phillipe now claimed to want her back, calling often and saying he made a lot of mistakes. Victoria, newly married and with a new baby, persuaded Sabrina to live at Newman Ranch during her stay. Sabrina began spending a lot of time in the company of Victor Newman, who was recently divorced from his wife, Nikki, and was living alone at the Newman ranch. They began speaking French to each other and shared their love of art. About the time Sabrina tried to tell Victoria of her growing romantic interest in her father, Victoria told her how much she hoped her parents would reconcile for the umpteenth time.

Though her art preference was Modern where his was Classic, Sabrina convinced Victor to invest in Modern art after a trip to Los Angeles in which Victor wooed and won her. On returning to Genoa City, Victor decided to open the city's first art museum in the ground floor of a building Nick owned; a building on which Victor just happened to own the mortgage. The building also headquartered the Restless Style magazine on an upper floor. Sabrina decided she had to tell her friend Victoria that she and Victor were having an affair. Victoria was aghast, called Sabrina an opportunist and threw her out of her house. Sabrina made several attempts to reconcile with Victoria, but was continually rebuffed. Victoria eventually quit Newman due to the friction with her father and with her half-brother Adam usurping her position, and went to work for her mother at Jabot. After only a month together, Victor presented Sabrina with a lavish ring and popped the question, to which Sabrina said yes. The next day Adam accepted Victor's offer to move to the ranch to get to know him better, and moved in. Sabrina was not thrilled with this idea, as she and Adam did not get along since each thought the other was an opportunist, but they ended up bonding nicely. Nikki reacted to the news of Sabrina & Victor's engagement by eloping with David Chow to Mexico.

It wasn't long afterward that Sabrina announced that she was pregnant. Victor was thrilled. (Strange considering the man has had two vasectomies.) After many discarded ideas, Victor and Sabrina decided to get married in an old barn near the ranch, and Victor had it cleaned up and decorated beautifully for the occasion. Since Victoria and Nick were still on the outs with them, Victoria turned down Sabrina's offer to be her matron of honor, and Adam was asked to be best man without Victor even consulting Nick. Unable to get any of her other friends from abroad to attend, Sabrina chose her new assistant Jana Hawkes as her maid of honor. Victor's daughter Abby and Nick's daughter Summer were adorable as flower girls. The day before the wedding, much to her displeasure, Sabrina's estranged mother Zara showed up. Nick attended the wedding, and although she tried not to go, Victoria, J.T., and baby Reed showed up just as the bride was walking down the aisle. Victoria caught Zara taking photos of the wedding to sell to the media, and she managed to get the memory card out of the camera to foil her plans. Victor and Sabrina left for Paris on their honeymoon where Victor bought her a chateau. Back at the ranch, Adam caught Zara taking a video tour of the ranch to sell, stopped her and later kindly ushered into a limo and onto a plane with a one way ticket home. During the wedding, at the stables with her new horse Athena, Nikki received a devastating phone call from David telling her that he could no longer deceive her about his gambling and that he wanted a divorce. But the next day David appeared begging Nikki to give him another chance, and Nikki was trying. On returning from their honeymoon, Victor ran into Nikki and saw her upset, but Victor left when Paul interrupted saying he was meeting her. Meanwhile David, on a business trip to Hollywood, cut it short to gamble in Vegas; where he was spotted by Gloria losing big at the roulette table.

As Victor predicted, the first edition of his son Nick's Restless Style magazine/webzine did not do as well as expected, so the second had a hipper cover featuring hot singer Katy Perry. Then Adrian Korbel was hired to do an article on Sabrina and the Newman Gallery for the 3rd issue, to which she and Victor approved. Victoria stepped up as a last minute replacement for the cover which was done in a Hollywood retro style. Though Adrian stumbled upon a rumor that Sabrina had wrangled an exhibition for her lover Phillipe when she was Art Curator at the Pompidou Museum in Paris which could shed new light on the latest Mrs. Victor Newman, he decided not to make a big deal about it. But Jack did some further research and turned Adrian's article into a scandalous one that upset everyone, but the magazines sold into a fourth printing. Jack had sent Adrian off to Australia to do another article, so he was furious when he returned and found out what Jack had done to his article. Assuming Nick was in on the scandalous article and for Victoria's turning against Sabrina for marrying her father, Victor cut them both out of his will as he added Adam and Sabrina.

The 2008 Charity Gala, organized this year by Sabrina and Victoria under the watchful eye of Kay Chancellor, was in full swing with all the Genoa City regulars attending in cocktail party attire. Devon and Ana entertained singing with a chorus. Chloe chose the occasion to announce her pregnancy by Cane just as Cane was proposing to Lily. Adam left Heather on the patio for a moment when mobster Walter tried to hit on her. Nikki and David were playing the happy couple one last time before Nikki filed for divorce. Victor told Sabrina he would send a limo for her, when he left with Michael to meet with Phillipe at the ranch to confirm or deny the story about him and Sabrina. While David was spiking Nikki's drink with enough morphine to kill her, Phillipe was telling Victor the story as he told it to Jack Abbott not Korbel for the article. Paul and J.T. figured out that David had mob ties and feared for Nikki's safety, arrived just in time to take the drugged Nikki to the hospital. Meanwhile David searched for Nikki, gave up and waited for his limo at the front door. Sabrina was there waiting for her own but was not feeling well and begged David to share his limo to be dropped off at Newman ranch on his way home. David relented, noticed the driver was not the one who dropped them off, but called them Mr. and Mrs. Newman. Eight miles down the road another car ran them off the road and the limo crashed, killing the driver instantly, and seriously injuring both David and Sabrina. Victor was notified by Michael that David and Nikki's limo had been involved in a major accident, so Victor went to the crash site. David was still being worked on by paramedics, and "Mrs. Newman" had already been transported to the hospital. Victor had flashbacks of the happy times with Nikki, thinking she could possibly be dying. Then he noticed Sabrina's earring in the limo and it dawned on him which Mrs. Newman was in jeopardy. He climbed out of the wrecked limo and accosted David Chow, demanding to know if Sabrina was with him and why. But David was too far gone, and later died. Victor rushed to the hospital to find Sabrina in a near death state. He refused to believe she would die and demanded Michael order specialists, dialysis machines, and organ donors to save her. The family was there to support Nikki who came out of the morphine overdose just fine. Once they heard about Sabrina, Nick and Victoria tried to see her but Victor kept them at bay. Eventually Victoria, who after discovering the lies that Jack Abbott put into the article, needed to let Sabrina know that she was wrong about her and ask her forgiveness. Although she did get to see her and they had a nice chat about old times enjoyed together, she never did get to tell Sabrina she was sorry before Sabrina died alone after asking Victor to get her some ice chips. After her death Victor was left alone to say goodbye, and vow to get even with those who had killed her.

Nearly two months later, Victor still in mourning, had an apparition of Sabrina while in her art studio. She asked Victor to dance, and he replied, "Finally you have come back to me."

In June, 2009, Ashley took a walk in the garden and had a vision of Sabrina telling her she was fine with Ashley being pregnant with Victor's child and making him happy.

In December 2010, Sabrina appeared to Victor in a Scrooge-like experience as the ghost of Christmas present and showed him Adam alone in jail, framed for a murder he didn't commit. Victor watched his beloved Ashley become engaged to Tucker, Diane missing Christmas with her son Kyle because Victor made her work all weekend. Victor saw the rest of his family celebrating Christmas at Victoria and Billy's, his younger children missing him, the older ones glad he's not there to spoil the fun, and Nikki wishing him well in the spirit of Christmas. Sabrina left Victor warning him that he was doomed if he continued to live refusing to see things outside of his own narrow point of view.