Saving Casey — Liza O'Connor

When eighty-year-old Cass Goldman learns she has inoperable cancer, she decides to end her life, peacefully on her terms. So imagine her horror when she wakes to find herself in a hospital with strange rich people staring at her. It's not until the doctor arrives to examine her that she realizes she's no longer old. She's in the body of a seventeen-year-old teen named Casey.
Unfortunately, her new body comes with some serious baggage. First of all, the kid has burned every bridge imaginable. Secondly, those ‘people' in her room are her outrageously rich parents and while the Dad seems friendly, the mother wants nothing to do with her. The moment they take her home to a horrifically huge mansion, which she dubs Tara, she's abandoned to the care of the butler.
While Cass is determined to turn this train wreck of a life around, doing so is far harder than she expected. In fact, without help, she'll end up dead just like the last occupant of this body. Thankfully, her dad has his hunky head of security become her bodyguard. Between her eighty years of life lessons and hunky Troy's help, she just might live long enough not to be jail bait.