I am looking for a chapter book about a girl who gets a babysitting job for the summer. Her parents had died, but she tells the family she's sitting for all kinds of stories about her parents and I think her siblings, even though her parents are gone. She lies to this family all summer but I can't remember how the book ends. I think it was called "Kitty" or something like that and I have the name "Tina" in my head about it too...

Thanks!