Relatively Close (2020)

Anna, a 17 year old girl, struggles to accept her grandmother's dementia. Her mother, Rachel, tries to get her to go, but Anna can't stand that her grandmother Katherine can't remember who she is. As punishment for not talking to Katherine during a visit, Anna is given an old box of keepsakes that belonged to her grandmother. While searching through the box, she finds that Katherine had a friend named Caroline. In an attempt to get Katherine to remember her, she pretends to be Caroline. This theory works, but Rachel can't know about it.