So it's kind of sketchy. She may have meant the management doesn't allow it. But it should be posted if that's the case.
The main difference between posting and not in CO is that if it's posted, the owner can ask you to leave and if you don't, hit you for trespassing. If it's not posted, you could argue that you were not informed before entering. Either way, you'll be leaving because it's the owners right to refuse service.