My costco visit

So, the last time I went to Costco Caleb had to go the bathroom. Of course, I was in a rush and by the time he told me it was an emergency. I'm really not sure why he doesn't tell me before the situation becomes a crisis but that's usually how it goes with him. We get to the bathroom and a little girl (probably around five years old) walks in by herself. She did her business, washed her hands and then left the bathroom only to find that no one was waiting for her. First of all, who lets their child go to the bathroom unaccompanied??? So, I took her to a female Costco employee (who by the way made me wait for a minute or two before she helped me) and explained the circumstances. I figured the girl was going to be okay. She was wearing a Catholic school uniform. I did my shopping. Then, came back to ask if the girl was okay because I was concerned. The employee told me that her brother came to get her shortly after I dropped her off. Why wasn't he right outside waiting for her? When I was leaving the store I saw mom and the siblings. Why didn't mom take her herself? Doesn't she watch the news??? I think it's insane. The Costco employee told me I'd be amazed at how much this happens. She then went on to say that "most" of the time someone comes looking for the kids. Well, that's comforting to know.