Yes - get independent legal advice. When I split from my ex, the house was transferred to him and he bought me out. If you go to joint names then the debt will always be your responsibility - and your ex is not paying already, so that doesn't bode well. Get your own solicitor to write and say that if she wants to stay in the house, she'll have to buy it from you. She'd had plenty of time, and there is a solution already at hand with your potential purchaser. However - if you have children you do have an obligation to them. Get advice, don't hang about.