Something you might want to explain to her is that Ohio is one of the last standing Dower states. So she kind of is already on the loan. Dower simple is "1 can buy but 2 must sell." If she doesn't agree to selling and you do it against her will she still owns 1/3 of the property at stake which would be all of your properties.
Something else is how you are doing it. Just by telling someone that they need to do something because it helps YOU, doesn't always work. If there's anything that would back up my point is Dale Carnegie's book "How to win friends and influence people."
These are his twelve steps to get people to get to think on more parallel scale:
Win people to your way of thinking
- The only way to get the best of an argument is to avoid it.
- Show respect for the other person's opinions. Never say, "You're wrong."
- If you are wrong, admit it quickly and emphatically.
- Begin in a friendly way.
- Get the other person saying "yes, yes" immediately.
- Let the other person do a great deal of the talking.
- Let the other person feel that the idea is his or hers.
- Try honestly to see things from the other person's point of view.
- Be sympathetic with the other person's ideas and desires.
- Appeal to the nobler motives.
- Dramatize your ideas.
- Throw down a challenge.