Most return visits end up going nowhere. Hopefully your neighbor will naturally fizzle out as a return visit. I think you have to be careful how much you say because if she becomes a witness you may end up with an unfriendly neighbor.
I've thought about giving a return visit the link to jwfacts but then I also wondered if the return visit asks the dubs visiting them some of the issues they read about and get answers that satisfy them (even if they're crap answers) it may speed up their indoctrination instead of stopping it.
Imho I would just mention to the neighbor that you saw the witnesses the other day at her door while you were home sick and wondered what's up. You will probably be able to tell right away what she really thinks about the dubs.