Time Travel book. Can go back and forth in time, she stays in the past (they fin her photo in the yearbook after she goes missing). Read before 2018.k Spoiler.

[Jessica]

Awhile ago I read a book about a girl who (somehow) could travel back in time. She makes friends with people in the past and even saves one of their lives. She is a bit of a trouble maker in the present, so she decides to stay in the past. At the end, a man she befriended, who owns (I think) a movie theater gets money left to him by someone with a similar name. They trace it and find a picture of the girl in an old yearbook proving she decided to stay in the past but willed him money. Help me find the name!