I had a similar problem with my 5 year old cousin a while ago.
She, little angel that she is, absolutely refused to use the MENs room, and she had to go potty. After trying and failing to negotiate with her for a while I thought that was it, we were at a standstill, we were deadlocked. We'd be staring each other down until she peed her pants in public and I'd be forever known as the guy who made his baby cousin pee her pants in the shopping mall.
I was caught in a battle of wills with a 5 year old, and I lost. As it turns out, her will is much stronger than mine, who would have thought? - or in Aussie-speak 'whodathunk?'
She grabbed my hand, turned on her heel, marched through the door to the ladies room and very loudly informed everyone to cover up because "(her) cousin is coming in, he's a boy, and if you don't like it you can go because (she) has to go potty NOW!"
