Celeste is a bit of a mystery. Over the years, she has been referred to as 'Celeste Perrault', 'Frankie Perrault', 'Frankie Brooks', and 'Francesca Perrault'. Her real name is most likely Francesca Perrault...although Caroline always referred to her as 'Frankie Brooks', she was the sister of Lexie's adoptive mother Grace, who had married a Brooks. Presumably she assumed the name 'Brooks' when she was on the run from Stefano.
Celeste appeared on the scene as Stefano's henchwoman and New Orleans mistress who kept an eye on Gina (really a presumed dead Hope Brady) for him. She helped Stefano kidnap John when he came to Maison Blanche looking for answers about his past, but her soft spot for him led her to give him clues as to how he could escape. When Marlena Evans arrived in New Orleans, looking for John, Celeste aided in her kidnapping too, but she was in love with Stefano at the time, and quickly became jealous. She leaked gas into the cell where John and Marlena were being held, and started a fire, which ended up burning the entire place down.
After the fire, Celeste came to Salem where viewers learned she was 'Frankie Brooks' to a number of Salem residents, particularly Lexie Carver, who called her Aunt Frankie. Celeste's role in Salem was to plant Hope's memories in Gina, but when she dropped the book she was using, Billie Reed found it and used it to expose the truth. At the same time, though, Lexie had recently found out she was adopted as a baby. She asked Celeste for the truth...Celeste knew, but lied to her to keep her safe.
Lexie eventually figured out the truth, and she and Celeste were able to form a loving mother/daughter bond. Celeste backed away from her former life of crime, and set about being a mother. Unfortunately, since then she has been used primarily to have 'feelings' whenever something is about to go wrong. She had a key part in the Salem Stalker storyline, seeing a premonition of death before each murder.
Not until after the last victim had been murdered did Celeste start having visions of the dead really being alive, but as soon as she did, she told what she knew, and her visions played a part in bringing the survivors home. After learning that Sami and Lucas were engaged, she began having visions of Sami ending up with Brandon.
Celeste returned to Salem when she learned that her daughter, Lexie had disappeared. She moved into Abe's house to help Abe care for Theo. Desperate to find her missing daughter, Celeste struck a deal with E.J. DiMera to get information about Lexie's whereabouts. Celeste pretended to plot with Sami to kill E.J. when in reality; Celeste was working with E.J. to test Sami. E.J. wanted see if Sami could really kill him or if deep down she had feelings for him. E.J. continued to use Celeste's services when he asked her to perform a paternity test using her psychic powers to determine if he was the father of Sami's twins. Celeste told E.J. that he did indeed father one of Sami's children.
Months later, Lexie was discovered being held captive in the tunnels under the DiMera mansion and Doug's Place. Celeste helped nurse her daughter back to health and reunite Lexie with Abe and Theo.
Celeste hadn't been seen for years when in the spring of 2012, she ran into the Carver living room, urging Lexie to see a doctor right away. Celeste told her daughter to have the tests done that day because she was in terrible danger. It turned out that Celeste's fears were founded. Lexie had an inoperable brain tumor.
But, before Lexie died, Celeste had a piece of good news to share. It turned out that Celeste had recently reconnected with her long-lost son, Cameron. Celeste explained that Cameron had been taken away from her when he was five years old, and she had not mentioned him before because the situation was too painful to talk about.
Lexie was happy to meet and spend time with her new brother, even if it was just for a short period. When Lexie passed away, Celeste, Cameron and the rest of Lexie's family gathered to mourn their loss and celebrate Lexie's life.
After the funeral, Celeste moved back to Chicago, but continued to visit Salem from time to time.