I loaned a friend $20,000 for a downpayment and also co signed for them. I have the check in writing but there was never a pay back date since I wanted her to get some wiggle room. Can I put a lien on her house?
No. It's too late for that. Obviously you already know you should have gotten the repayment terms settled up front. I understand you wanted to save some money up front by doing this without a lawyer. However now it's going to cost you more to get this fixed.
Good luck.