Take feelings out of it. Your in public. Kids or adults. And somebody has a camera. There is nothing illegal about that. If it was illegal then you would see signs at a park saying no taking pics of kids. Makes sense right. The reason you don’t see those signs is because it’s not illegal.
don’t believe me? Look it up and tag me

Maybe I’m wrong. I don’t think I am.
If it was illegal to take pics of anyone who did not consent to it in public then paparazzi would not exist
Edit:
As a general rule, if a photographer is shooting from a
public space, such as a street or a park, he or she will usually have the right to do so without the consent of the subjects. Generally speaking, if you can see it from a public space, you can take a picture of it.
Is Street Photography Legal? | Artrepreneur
If I was a parent and saw someone filming my kid yeah their will be a discussion. In the eyes of the law tho if the person is in public and they are filming someone in public they are free to do so.