I know she spent $150 for a 4 year-old’s hair. Really?
That’s her business, not yours. Unless she came by the money illegally - and we have no evidence of that - she can do what she likes with her money.
Just as you can.
You aren’t the moral arbiter of what the rest of us can do with our resources - and how a busy woman decides to manage her child’s hair is none of your business, either. (If the government tried to judge your financial life that way, you’d scream bloody hell.)