I’d be hoping that you’ve educated your daughter with enough tolerance and ammunition to deal with the situation herself.
Kids fight all the time, and managing the little mites propensity for jealousy, arguments, tussles over a football etc is all part of their growing up process.
My kids 7. He’s very tolerant as we’ve taught to continue to ask people not to say/do anything again, and repeat. I quote happily taught him that if another kid deliberately punches him and does not stop when asked punch him back.
Shock horror gasp I hear the PC brigade go, but they need to learn to stand up for themselves correctly. And this involves making a situational judgement taught by the parents.
I’m sorry your daughter got punched, but the other child got punished, and your responsibility is to ensure she knows how to prevent it happening again.