The movie I’m trying to remember is an old black and white from either the 30’s or 40’s. It’s about a young female teacher that falls in love with a man, but he ends up marrying her sister, and then they have a daughter. After the teacher’s sister dies, she ends up raising their daughter. Can’t remember if the man dies. She lives for many years and becomes a beloved teacher in her school. At the end the school is set to be torn down. They ask her to come to a ceremony because the school is being demolished, but it ends up being a ceremony just for her. All of her former students are there to praise her and sing to her. At the end she goes home happy and content, falls asleep and dies an old woman.