Rick,
Even though the agreement contains "generic" wording, as Rich said, it appears to pertain only to the apartment.
I'd talk to her and explain that I would tie them up in 1st ammendment litigation so long thier grandkids would be fighting it, and possibly, if they get any section 8 funding (I know the one here does), that you'll be filing a complaint with HUD regarding your 1st ammendment violation.
IIRC, a complaint can cause a delay of funding and apporval for new tenants until the problem is resolved.
You could likely file a federal action on the same thing without an attorney
Just because she's a prude desn[t mean the rest of the world finds it offensive!
If there are a lot of kids in the area, then I can see what she's talking about to a degree; however, it's not her place to be the moral police