I don't understand how you have money and want to give it to your mom but aren't just living on your own/with a roommate/s and paying for your own things yourself? If you are an adult and/or not in school, your mother cannot claim you on her taxes, you have to fill your own out.

If you have a "plan" you are working on, saving X dollars for when you get married, then do that and to heck with what your mother says; you can chalk it up to her need to complain and inability to do so about the man in her life. Don't take it personally.

If you are just sort of saving money and/or spending it when you want something like restaurant/food, paying cell phone bills, etc. and waiting around to get married so you can get away then I would make a plan instead and figure out how to behave more responsibly so when I got married I would know how to save/budget money and would have a job, etc. Having and working a plan will take the sting out of anything your mother says as you will know what you are doing and why and what you want and your mother isn't part of that.

If your mother won't accept your money and you want her to, do the chore of going to the grocery store and filling the kitchen/refrigerator with food and cooking meals for the two of you for a week or something practical like that. Take over the things she complains about having to pay for you (if she is in fact paying them), with the exception of "rent" you should be able to pay what you owe, at least in kind (like groceries) or through work (cleaning the house, doing the dishes, keeping things picked up, doing laundry/changing beds, cleaning the bathrooms, etc.). She can only complain about what is there to complain about. If you are living there rent-free, figure out how to pay for your upkeep some other way.