She made a copy of the keys. If you want her to not return, you can buy another, interchangeable lock for this situation. Just keep old lock and key to change out later, if necessary.

If section 8 considers her out, you can consider her out as well. Section 8 will not defend you. Anything left at this point, remove the stuff to where she will not have access to it.

I wouldn't worry about legal aspect, because if a set of keys is back in my hands, I consider them out.