line your lot line with 4 or 5 of the cat traps, when she see's her cats in them maybe she'll get the message.
Just try to get to the trap before her, what is she gonna do call the cops for you trapping her cats in YOUR yard, not illegal. Heck she would be trespassing on your land to get to the trap.
Also does your town/city have a animal limit ordinance?
Usually each pet must be licensed with proof of all vaccinations.
Is she licensed to run a rescue from a residential property, that alone could be illegal.
sounds like this is gonna be a bad neighbor for the long haul