They share a child & my sister in law (ex-wife) takes care of the child while the father goes to work but she signed full custody of the child over to him.

Hello h:

Who has custody and who works doesn't matter.. Who owns the house is what matters.

excon

I agree with Ex , there is no marital relationship and no joint property claims. She is simply a visitor.

"The house?" What does that mean?
If it was the marital house, then who got it was determined by divorce decree.
If one party is buying the other one out, then it's who is on the deed.
If it's up for sale or foreclosure after the divorce, then who gets to live there pending sale is also part of the divorce terms.

If the divorce isn't final, then either party can live there until it is.

I agree with Ex , there is no marital relationship and no joint property claims. She is simply a visitor.

Not necessarily. You have been giving a lot of questionable legal advice. We take pride in the accuracy of the advice given here. Please be more careful that you research your answers.

There is not enough info here to give an accurate answer. First, Any question on law needs to include a general locale as laws vary by area. Second, what went on in the divorce? Was the house shared? Did it go to the husband? Was there a written agreement for the mother to continue to live there? How long has she been living there taking care of the child since the divorce?

Please provide these answers so we can give an accurate answer.