Here is the deal. My nephew has been living with my mother in Virginia. She allowed him to stay there in order to help him out with school. She even got him a car. He is 26 years old now and has been there for 6 years. He is now stealing from her and smoking in the house, which is not allowed. What steps does she need to take to put her grandson out? Thanks in advance for any information you can provide.

Give him written notice that he is to move out. If he does not move out, file in housing court for a formal eviction.

Also why not report the theft to the police?

It doesn't matter that he is a family member. He need to be treated like any rental tenant. She needs to follow the process for eviction in her area.

Whenever something is "missing", he says he did not take it. She tells him there are only the 2 of them living there.