The name of Bitcoin now is very common on the internet or on any social media platform. I don't why your mom thinks that you're just a dump upon holding Bitcoin and she thinks this doesn't have a value. Selling your Bitcoin isn't kind of proof that your mom will believe in you. Even you will search on the internet how much the value of Bitcoin to dollar rate.

Take note that before you will rush cashing out your Bitcoin into cash just to impress you mom, just ask first yourself if you will self your Bitcoin, it should be your profit was there.

Anyways, I agree suggestions on the first page, Bitcoin ATM (Coin Radar)through the help of and P2P exchange is a good place to go if you want anonymous transactions.