Unraveling Isobel - Eileen Cook

A darkly comic novel that "combines the perfect mix of mystery and romance to create a delightfully creepy chick lit-y ghost story" (School Library Journal), from the author of The Education of Hailey Kendrick and Getting Revenge on Lauren Wood.
Isobel's life is falling apart. Her mom just married some guy she met on the Internet only three months before and is moving them to his sprawling, gothic mansion off the coast of nowhere. Goodbye, best friend. Goodbye, social life. Hello, icky new stepfather, crunchy granola town, and unbelievably good-looking, officially off-limits stepbrother.
But on her first night in her new home, Isobel starts to fear that it isn't only her life that's unraveling--her sanity might be giving way too. Because either Isobel is losing her mind, just like her artist father did before her, or she's seeing ghosts. Either way, Isobel's fast on her way to being the talk of the town for all the wrong reasons.