Am I a bad parent for being a little bothered by this?

Alot of times my daughter (6 years old) is around new people or hanging out with other kids, she starts acting like a baby. I never seen another kid her age act this way which is why it’s confusing for me. And I really don’t know why she does it, maybe she’s excited in the moment? Idk.

But she will literally act like a baby, flap her hands, make baby noises, sometimes act like she doesn’t know anything and talk like a baby (not using her real voice and talk as if she doesn’t know any words) it’s really hard to explain but when she’s back home she’s herself again. Normal voice, no hand flapping, no baby noises, none of that. The big girl we know her to be. Sorry if that sounds mean but I’m just bad with words. And this is not EVERYTIME we are out or around other children but she’s done it enough for me to question why??? For example she has people and some kids that she sees a lot and doesn’t act this way. Also doesn’t act this way at school because I’ve asked her teacher.

I’ve asked her before why and she just says shrugs her shoulders. Is it just to grab attention? Is this normal?