my friends son kicked my son in the face

so today I was hanging with my friend & her child who's 5 kicked my 13 month old in the face causing his nose to bleed this bitch literally just told her son to stop that's not nic , so I left her sitting at the store with all her groceries so I can take my son to the hospital to make sure he didn't hurt him that bad .. im more upset she didn't discipline her child & I didn't feel comfortable popping someone else's child cuz I wouldn't want them to discipline mine.. I'm so heated