You did a good thing by trying to help out the children. Boundaries are something I would encourage you to talk with the daycare staff. Explain the circumstances and ask them to set boundaries on the visits. Many daycares have some guidelines for visitors to follow. You were helpful in getting the children placed there and talking to the director of the facility seems a very reasonable step in trying to resolve the situation. Your in-laws may be trying to compensate for their mother being absent and may not realize how disruptive they are being. My guess is this is a discussion the director can have with them.