Responses
The thing is that babies don't really care. Hair is some weird thing on someone's head that they feel that it's fun to pull. Sooha could have not made an angry face or "yell" at the kid, but neither Sooha or the baby knew any better. What the mother could have done, or the father, was gently pull the baby's fingers away from her hair which neither did. Sooha could've done that too but she didn't.
But I mean...that baby was pulling her hair and wouldn’t let go. She didn’t yell at him she just looked at him angrily. Not like she meant to make him cry or whatever.