A lot of parents just can't stop being parents. My DW's Mom is like that. As an example, we were visiting them for dinner a few weeks ago and the subject of spending money on house repairs/etc. came up. Instead of actually LISTENING to what we were talking about, she immediately asked, "Do you need some money? I can help you!" We have been crystal clear that was are A-OK financially yet it falls on deaf ears. It is what it is.
Take the money and tell her you put it into Bitcoin. She probably won't offer again.