LOL
I was opening this up dreading to see those spandex bike short things or something.

Oh yeah, those are hot pants, nevermind...

I've heard of lots of people using different sized boys briefs and using a pad or liners when they have a female in heat with good results.
However I'd be scared to bring a female in estrus to a doggie populated area. She might behave fine, and you might not have a problem with her getting accidently bred. But, is a big but, it'll put the other dogs on edge and could cause some aggression problems amongst them. I used to train with a bunch of GSD breeders who had intact males and females. If any of them had a female in heat at home and brought one of their other dogs in, then ALL the dogs were tense jittery and the intact males where REALLY disoriented and edgey. Just a word of warning.

So lets see some pix of this pup when she gets her hot bitch pants on. LOL