SOLVED. YA novel I read around 1997-1999, about an adolescent girl who befriends an eccentric classmate who eventually teaches her how to lucid dream. [s]

[Theo]

I think the girl who learns to lucid dream communicates with her grandmother in her dreams, who might be deceased. The girl who teaches might be named Mina, blonde, with old fashioned clothes. One of the characters might be Jewish?

[Andria]

I think this is Missing Girls

[Theo]

omfg, THANK YOU! YES, it is!!!