When you filed your LLC with the state it showed both your names on it. Does she have a copy?
When you file your taxes for 2017 you understand that you have to file a partnership return and issue her a K-1?
Has the rental made any money? Did you give her some?
One way to assuage her hang up is to write up an LLC Operating Agreement showing that she has the same ownership and interest as you do. You can find samples on the internet.
Or, since your relationship is now obviously hostile, buy out her interest in the property or sell it.

