We both signed an agreement (in front of a notary) to have the money paid back by now. What can I do to force her to pay me back? She does not respond to phone calls and even now has turned her phone off.

Take her to court... and don't waste any time doing it. When you win (assuming you do)... make sure you get a writ of garnishment from the court, so you can go after her bank accounts or try to have her wages garnished.

Winning is the easy part. Collecting it is the hard part.

Thanks so much. Just looked up the paperwork to file against her. I think you are right - collecting will be the hard part. Thanks again!