In fact, there is no way to solve the problem of mother-in-law interfering in her own education. First of all, you should let the child know that you are her mother and your orders or requirements must be enforced. It's no use coquetry to the old man. Of course, the father of the child will also come out to play the bad COP. Secondly, we should communicate clearly with the elders at home and explain the strong relationship. Blindly doting will only harm children. For children's education, the strictness must be strict. Finally, there are some things to be done to cultivate children's consciousness. How to make him have a judgment in his heart is not only good for his study, but also of great help to him in the future. Children will learn to refuse to say no even if their elders love them. Form good habits.
If you think your mother-in-law's idea is wrong, you can take your child to another room or a place where there are few people, make sense, guide the child to understand right and wrong, learn to think, and let the child judge what consequences that will cause and learn how to correct it. I will communicate with my husband and mother-in-law afterwards. When educating children in the future, let mother-in-law pay attention to establishing parents' prestige in front of children. If there are different views, we can talk about it afterwards, and the attitude of the whole family should be the same. If the mother-in-law is still the same, then reduce the number of visits to her husband's house.
But don't directly conflict with the elders at home, which is not good for family harmony and children. I hope my answer can help you.