AAAwwww first of all
to little Lulu. Those things HURT!
Check to see if the stinger is still there, if it is use your fingernail to scrape it out. Next clean the stinger puncture with a bit of peroxide. You can use several things to help -- benadryl ointment, meat tenderizer made into a paste, ammonia (stinky, but it works) a cold compress, if you "chew" I have always heard that chewing tobacco will take the sting out of a bug bite.
I hope she gets to feeling better real soon, if she starts to show any unusual swelling or has trouble swallowing or breathing, then hi-tail it to the emergency vet.