What is this Lifetime movie i think?

A girl is having a hard time or is in trouble cant really remember what she did or w.e all i remember is that she moves in with her grandmother at some nursing home an starts actin nice an putin on a whole act an then she starts finding out about her grandmother doin something she shouldb't be doing or the grandmother starts finding out about her,and i think it has something to do with the granddaughter finding mail from her mother or something but not sure an another thing i think the grand daughter is played by a fairy known actress sorry for the bad punctuation an bad description