I WISH I’d seen the TV interview that writer/director Marielle Heller, actress Bel Powley and actor Alexander Skarsgård gave to the International Movie Database for the 2015 Sundance Film Festival.

Those three people made “Diary of a Teenage Girl”, which explores a delicate topic that’s happening every day in every community without discussion or parental guidance. Every girl experiences it during that dangerous time when the challenge comes not merely from first menstruation, which mothers explain with varying degrees of completeness, but from that wonderful whole-of-mind and whole-of-body collection of yearnings, stimuli and compulsions that form full-on sexuality.

Minnie (Powley, giving an impressive performance) is 15. Her mother Charlotte (Kristen Wiig) and father have separated. Charlotte is in a sort of relationship with Monroe (Skarsgård).

There’s no other way to tell it. Novelist Phoebe Gloeckner has written Minnie as a child who won’t wait until she reaches the age at which adult lawmakers have decreed that she is mature enough to sexually engage. She’s ready now. And her choice of partner to launch her sexual life is Monroe.

“Diary of a Teenage Girl” is confronting, frank without being salacious. It’s sympathetic. Most of all, it’s credible. Its MA classification should not deter a parent wanting to provide an adolescent daughter with a credible view of what lies ahead.

At Palace Electric