How many movies have Karen Grassle and Melissa Sue Anderson acted in together?

They have worked on 3 movies together! Their first movie together was Little House on the Prairie (1974) while their highest rated movie together was Little House on the Prairie: A Merry Ingalls Christmas (2014). They have not worked together since Little House on the Prairie: A Merry Ingalls Christmas (2014). They are most known for their family films together.