The decision of your mom is right. You can't force anybody to be involved in Bitcoin to make an investment in Bitcoin. It A human nature not to believe until they do their own analysis, In this case, your mom first does not accept but when she hears from another person she believes. Bitcoin needs consistency and patience if you force someone then maybe he will work for just one or two days and then he will be bored because you force him to do this instead if you tell them nicely what is bitcoin, how it works, its benefits and also your profits are taken from bitcoin then I think your words will effect on him and will start some research on bitcoin and at last he start investing in bitcoin.
I personally had a negative experience of communicating with people when I told them about Bitcoin and other crypto projects. At that time, they considered me a fraudster who was trying to deceive them. This happened several times. Since then, I haven't told anyone. People should make their own decisions without the intervention of others.
It's a pity that I went through such a process, and maybe it's all for the best. There is also some experience here.