Legal Question in Wills and Trusts in Pennsylvania

No, but I have a qualifier. I don't know where your son resides, but generally the law is that inherited property stays separate in the event that your son and daughter-in-law divorce. What this means is that if he inherits it, he keeps it.

The problem can arise if his inheritance is commingled. For example, he inherits money and he puts it in a joint bank account and uses it for the family. Its now marital property, not separate property. Same with land - if he puts the wife's name on it, he has made it marital. Or if she helps it increase in value it might be deemed marital to an extent.

My advice would be to see an attorney to do a proper will or trust so that assets go to your and possibly his children so that assets are kept as much as possible out of the daughter-in-law's control.