She needs to introduce her son to the joys of lubrication.
One issue that really bothers me is the prevalent advice to "get professional help" or to "see a psychiatrist". With such advice, people lose the ability to solve problems on their own. Additionally, such "professional help" is most often unqualified even if certified, and are no better than if the person addressed their issues on their own. What bothers me the most about it though, is that taking such an issue to "the police or social services" takes the issue outside of the home and gives others control over the family's life and happiness. Once that call is made, the family gives the decision making process over to the "police or social services". Thereby losing control over their own lives.
There is rarely a sufficient reason to elevate problems beyond the current structure, such as making a family problem public or taking a workplace issue to a higher management level. If it happens in the family, then you keep it in the family. There is no reason to get others involved, just fix it yourself and move on.