Canning is your therapy. Just like needlework and other crafts are mine. Thank her for her concern and then follow CG's advice. She is going to be your MIL as long as her son is your husband. (Hope it is for many, many years.) So you don't want her for an enemy.
The only thing that concerns me is why is she so worried about your finances? I don't even discuss with my children what they do with their money. It is an area I have always considered private. If I should choose to buy a Porterhouse steak, that is my business, not anyone else's. The only reason my kids know mine is because of my advanced years. They have the NEED to know, not the desire.