My close friend is a single mother with kids ages 3 and 5. She works full time as a nurse and has been feeling overwhelmed with work and her kids recently. I offered to come over to give some moral support, knowing that the kids tend to be overly aggressive and I don't have any kids of my own. Anyways, while I was there, the youngest son was continuously hitting his older sister despite my friend telling him to stop. After several warnings, she pulls him into the bathroom. Then I heard a few loud slapping sounds along with the her son wailing. What should I do? Is this okay!?