I know it's hard... but sometimes when some group is strutting about with a big chip on their shoulder, just dying waiting for someone to knock it off, the best thing to do is just ignore them.
Do you think they really care about normalizing or mainstreaming drag queens to little kids or mainstream America? BTDT... Ru Paul did that in the 90's. Ship has sailed. Hell... maybe Monty Python did that in the 70's...
No. They're praying the WBC or some such shows up to protest, or some city official tries to order the library to ban the event. Then if/when someone foolishly rises to the bait, drag queens will be damn scarce on the ground in every blue city, and probably quite a few red ones, as all the libraries across the nation scramble to host their own story-time and show "solidarity".