I would appreciate any advice on this my move
First of, dragging your or trying to convince your mum to accept something she knows nothing about as a payment option is not advisable, you should start by educating her about Bitcoin and see if she'll be interested in it or not.
Scond, all you need to invest in Bitcoin is your money --> Bitcoin Wallet (I guess you know the right type judging from your last thread) --> an exchange (preferably Dex) to purchase your Bitcoin from.
As for the currency value, I guess you're not from a country that uses USD as it's official currency that's why the whole amount seems like a big amount to you, I can't really tell the country you're in since you've never made any post in your local board but you should try to start with a little amount, after all the first rule of investment is to "always invest what you can afford to lose".
TL:DR. Don't persuade your mum to use something she knows nothing about, let her continue using her normal Fiat, if she's interested in Bitcoin she can buy some and hodl. --> Always invest money you can afford to lose, that's basically everything you need.