#1 good job teaching your kids about guns
#2 CPS was doing it's job
#3 followup with CPS in the vein of 'Look I relalize you guys have to check out what is reported. However, Obviously as somewhere between 35% and 55% of households have firearms in them, simply possessing firearms is not enough to warrant you guys getting involved. I would like to see the report. I believe the report was made in bad faith to damage me. I am going to talk to the police about pressing criminal charges for making a false report."
Then do so.
Also, I really hope you still have the text message or whatever that says
"hopes one of the kids gets a gun and shoots the other in the face"
Point this out as not the words of someone who is mentally stable. Don't do this for vengance, do it because it really, truely, DOES indicate someone who has problems.
Edit to add:
Wow, you know she is running daycare with a felon on the premise? Do you know for sure it is NOT a violent felony he was convicted of? Don't you feel it is your obligation to reveal this truthful information to the correct people because it is a reasonably dangerous situation for the children to be in? To me, this is like seeing smoke coming out from under a door of a daycare center...you just don't walk by 'because I don't want to get involved'
You say you believe in Karma. How much Karma do you earn if the Felon ever does hurt one of those children?
Maybe Karma's way of balancing the fact that these friends lied about you is that karma arranges for you to have TRUTHS which should be made known to certain folks, and if this ends up harming those who harmed you, they get what is coming to them.