Daughter-in-law pays less and less attention to us now. She didn't tell us when she went back to her mother's house, but only told her son. She said she would leave now, and she didn't experience it.

She didn't tell you that it was her fault to go back to your parents' house, but you said it was your fault to leave without permission. You can't be too strict with her. What she wants to do is her freedom. You can't say you won't go without asking, but your daughter-in-law is really rude. You should tell your elders what you do. This is the minimum respect. Actually, you are both at fault.