From The Mixed Up Files Of Mrs. Basil E. Frankenweller AKA The Hideways 1973
In this children’s movies, a young brother and sister escape from the boredom of their suburban neighborhood and high-tail it to the Metropolitan Museum of Art in New York City. There they wind up hiding within the maze of hallways until the girl finds a beautiful white statue. She is captivated by it and becomes obsessed with trying to discover if it is really a Michaelangelo. This leads her and her brother to the mansion of a 70-year old recluse with whom the girl becomes friends. They begin sharing their secrets and talking about art.