It sounds as if both room-mate and boyfriend have been there for long enough that they will need to be legally evicted. If neither is on the lease, then the complex probably has no obligation to do anything, but they can come back on your (or you) daughter for any issues they have. Was it legal for her to have a room-mate not on the lease? I would serve BOTH room-mate and boyfriend with Notice To Vacate, or whatever it is in Mississippi. You could try offering cash for keys, offering enough to make it worth their while to leave peaceably.

Is roomie up-to-date on rent? If not, you may have other options, but if she is, you're likely stuck with whatever the notice period applies. You can contact the county of residence to find out what the requirements are she/you must meet.

Good luck