It is not what a professional GC would write, that is for sure. The fact that you are female is in the Common App, right? And you can indicate your ethnicity. Your financial status will be evident to the financial aid office (or if you don’t apply for aid, that says it all).
What your mom may not realize is that being white and female make it HARDER to get into many colleges. It isn’t something to flaunt. And I’m going to say… many admissions officers have a soft spot for low income kids who have achieved a lot. Upper class kids, not as much. So (1) your mom is pointing out info they can already find if they want to, and (2) she is highlighting info that isn’t helpful in your admissions story.
But… sounds like logic and facts won’t win the day.