Rent By the Room - Overnight Guests Policy?

[Shawn Blackwell]

Hello. I have aquired my first rental property and am renting out three rooms within it individually.
The house was advertised as a "safe space for women" meaning: no overnight guests (boyfriends, etc) which IS written into the lease agreement and was agreed to by all parties.

All three women signed the lease agreement. However, I am now receiving complaints that one of the renters is violating the agreement. The renter in question who is violating the agreement claims that these visitors are not "overnight guests" rather, they are just visiting temporarily between midnight and 4am.

It is causing some tension among the renters and I am not sure what my legal standing is as I did not clearly define what an overnight guest was in the agreement.  If I could do it over I would reword the policy to include visiting hours but at this point I am looking for some advice.

Can I tell the offending party that she is in violation of the policy even though it may be ambiguosly worded?