J & J,
If it were me I'd just tell her to F*** Off. Even if you signed a lease stating that you cannot have animals in the apartment once you move in you can get animals and their isn't a damn thing the landlord can do about it. Tell her to drop the issue or you'll call the city to inquire about her illegal apartment. Unless you haven't paid your rent for about 4 or so months their isn't much she can legally do to kick you out.