There’s a high level of difficulty in what Susan Sarandon pulls off with apparent ease in The Accompanist. As Sylvia, the foster parent of a young girl, she plays a character who is a little wacky and indulgent, kind and at times wise but with emotional baggage of her own. And Sarandon turns what might have been a blueprint for sentimentality and clichés into a believable, idiosyncratic, very present individual. In fact, all the performances in this feature debut from director Zach Woods , best known as an actor in comedies including the HBO series Silicon Valley, are grounded and sharp. They are the strongest element of a story about nine-year-old Emily (Everly Carganilla), whose grandfather and guardian (Kevyn Morrow) is showing serious signs of dementia. Aubrey Plaza , in a small role, plays an inept social worker who hauls Emily out of her house to Sylvia’s in a nearby New Jersey town. The Accompanist The Bottom Line A jumble of lovely and twee.…