Why didn’t she have her guns secured in some kind of locked strongbox? Snowflakes aside, it’s risking theft or unauthorized use to not have the weapons in a lockable container. Chained to something if possible.
If her nosy roommates asked her “what’s in the strongbox?” she could say “none of your d@mned business & stay the hell out of my stuff!”
“Do you have guns in there?”
“If you want to know for sure, get a warrant! But you’d better be ready to have me charged with something.”
And where does it say in the lease “no firearms”?
There is no indication that the lease says “no firearms”. That’s not what’s going on. The landlord is not seeking to evict her.
Basically the landlord is performing an informal mediation between quarreling co-tenants and suggesting that the most sensible solution would be for gun owner to move. But he’s not saying she has to. He is saying that if she stays and snowflakes all move, he’s going to be looking to her for the $6,000 rent each month. And he has every right to do that.