Ted, I think you were well within your rights to fulfill the obligation on your own. I can't tell from the original post when you told the whistle player she wouldn't be needed - if you skipped that unpleasant part and just went without her she might have reason to be annoyed.
As the 'front' for the band you probably did a good job of protecting the group, as well as yourself, from getting a bad rep by not cancelling on short notice.
I've noticed in watching the ebb and flow of people in my husband's band that these relationships aren't easy, and most egos are easily bruised. However, most players I've seen, who really care about the music, would rather take hits to their ego than have bad gigs. Life is too short for that.
PB