I remember a movie, but not enough details to just simply find it on google. I used to watch a movie in my childhood where a few kids (2 or 3) were the protagonists and there was a woman antagonist. Kids word kid apparel and coats. The woman was probably 30’s maybe 40’s even and wore 1920’s style clothes with one of those weird hats that are close to the head. In the end she is defeated and gets thrown into a horse pen where the horse poops and she faints somehow. Then the kids watch, laugh and run away off screen. I remember the woman had brown hair and they were at some sort of convention.