I know it's some sort of pin

Ran across this today looking through old finds, and assume the GS is for General Service, but just wondering what era/war? I or II?
It’s about the size of a penny. And appears the mark across the back was where the pin was.

LOL, never mind, just found it.

I thought surely that cant stand for Girl Scouts…

and don’t call me Shirley…

Sure enough