I'm a woman and I have to shave my upper legs, not often, but hair does exists on upper legs. Your mom needs a dose of reality.

I shave my thighs. I definitely grow hair there. wait till mom learns about puberty

Meanwhile, your dad the Sasquatch strolls into the kitchen in short shorts and asks your mom to shave his back.

I'd put money on your mom having just gotten back from shaving her mustache.

Your mom is stupid if that's what she thinks.

Wait until she hits menopause and starts growing hair everywhere and then call her a freak.