Occupant problem with apartments?

I visit my fiance in her apartment. I occasionally stay night. Mostly she stays with me. My apt. has no problem or even know or care. But her apt. is giving her lease violations for unauthorized guest. ? Saying that if somebody visits 6 times a month they need to be put down as an occupant. I find this hard to believe her lease says anybody that stays for 3 consecutive days. Nothing about visitors. If im correct an occupant is somebody living in the apt on a continuous basis. Im confused to why they are harring her for no aparent reason. We both are quiet people and are just waiting for our leases to be up so we can move in together. These people are saying if they see me one more time they will evict her. Can they do that to her for just having a visitor. First off they cant even prove when and if i have even stayed the night there! Whats going on!