Bothersome lady

Picture an animal enclosure with grass, rocks, water.
Glass, 2 feet of space - several children within the 2 feet, and a railing. Adults are standing by the railing.
Multiple kids were going between the glass and rail to get closer to the animals.
This woman looked at me twice and said, “that’s not allowed”.
I replied, firmly, “she’s fine, we are the ones parenting”.
And she started chirping about us being so entitled. I told her to mind her own business, please.
My husband raised his voice a bit and said, “be quiet, have a nice day”, several times
She just kept on… we had to walk away. My child was wondering what they did wrong, and we explained while yes there was space, she was there for a moment, maybe no need to go that close but you’re a kid and everyone is taller than you atm, and stepped back out as we were about to go to a different exhibit. This lady ruined the first little bit of our experience. Just didn’t know why she had to tell us her opinion when there was no danger/signs, etc. that wouldn’t allow our kid to be in that particular spot.