Well I don't know why you think your mom should accept bitcoin  but if is for the purpose  of you holding it, then I don't think you're on the right track and I don't think your mom would want to give out her money just fir holding especially  if she doesn't  have the primary  knowledge  of Bitcoin.
I would also want to know if you've ever noticed any of her customers having bitcoin? Nevertheless, it is a nice move to make bitcoin  a payment option in your mothers shop but I don't see it as a welcome development  if your country has some restrictions to it and rather than putting your mom to risk, then I think you should simply focus on other ways to earn or buy to hold.