So you just want to convert it to usd and make it as a proof?
You dont need to do it.
Show your mom videos about bitcoin from well known news media channels.
It would make her thinks that bitcoin is a legit thing.
And then let her know about bitcoin.
Final step, show her bitcoin success story video.
But if you still want to convert it,
Just search on facebook, a bitcoin local enthusiast group.
Please be selective on finding it.
My mom is too stubborn to learn about new technology, I already converted a fraction of my btc currency
She just wanted to show her proof as too why I was spending SO much time using my laptop after school
At one point she told me that "playing on my computer wasnt gonna get me paid haa"
Bitcoin must be really rare to obtain here in california, since after I cashed out on a local bitcoin atm, there was people looking at me like if I just discovered fire or something lol
Thanks for the help tho