Impending doom on my baby shower PLEASE help!!?

My baby shower is tomorow and kids are a no-no (my apt is only 1400sq and if everyone brought their kids there would be 15 little kids running around) so I told everyone NO KIDS. Some of my friends even went out of thier way and hired babysitters/rearranged travel plans just so they could stick to the sans kids rule. Well one of the co-hostesses I guess was planning on bringing her husband AND there 9 year old, the other hostess who is actually the only doing all the work forgot to mention it to her. When I explained that it would make me look like kindve an *** if she got to bring her kid she said it couldnt be helped (but she had asked just 30 min prior if her husband could come and drink beer with my husband....so that says to me HE CAN WATCH THE KID) This kid is a MAJOR brat and WILL annoy the other guests. (I even kicked MY OWN 3 year old out with her daddy for the shower!) In fact this is the ONE KID I didnt want there most of all! (the few times she been over here she has stolen my daughter things!!!) What (if anything) can I do??? Or do I just grin and bear it? How to I keep this brats distractions to a minimum??