I've noticed that kids can't guess age well. If you don't act like parent they assume you're a kid.

I recently had a riveting chat with a 4 year old who was convinced I was a kid because I was talking to her about kid stuff like the value of saving trash so you can glue it to your next bottle rocket. She could not accept that I was grown.

Alternatively I once had a conversation with a 4 year old boy where I was a little more authoritative about not pointing out the arts butts on women nearby and he asked me who's mom I was so he could come to my house.

These were both strangers kids who just sort of started talking to me and came out with two very different conclusions about my age. Had nothing to do with my looks. It was super weird.