You really don't need to agree to anything until you speak to a couple of different lawyers to see what your rights are and what you need to do to protect yourself. Don't ever take legal advice from your ex either, that's another huge mistake to make, talk to a lawyer or two and see what exactly they have to say. Even if her parents helped depending on all of the details of the marriage and house purchase you may be entitled to some of the equity. I can't say for sure because I don't know all of the details.