Acclaimed artist Marian Williams Steele died of Alzheimer’s in 2001, leaving behind stacks of paintings and a daughter, Pam, who was determined to keep her mother alive by writing a book about her. The only glitch: Pam herself was diagnosed with Alzheimer’s at age 61, a year into the project. The Genius of Marian is an effort by her son, filmmaker Banker White, to finish Pam’s work and also pay tribute to her. This moving but never maudlin film chronicles the struggles of Pam, her husband, Ed, and her children to deal with what happens when the family matriarch can no longer calculate the tip on a dinner bill or, eventually, respond to simple questions. White lets Marian’s paintings and plenty of family video footage show us an irrepressible Pam, who modeled in her youth and by all accounts had a well-deserved happy life. There are no surprises in this film, but the force of Pam’s personality and White’s subtle, loving camerawork keep the viewer watching.