Diets & Weight Maintenance Support Group
Chat about how well your latest diet is -- or is not -- working. This group is a great place to find support and accountability as well as share success stories and valuable lessons with the community. From where to start to weekly weigh-ins, get help from others to reach your dieting and weight maintenance goals.

If that has not worked, then how about refusing to take the clothing.
My wife taught me a secret many years ago. When you have an ongoing issue like this think up a very short reply and use it EVERY TIME your mom puts you in that position. Something like:
We have talked about this mother. I will not take your hand me downs.
Edit the language to best suit your situation, and say it exactly the same way each time. You may have to walk away just after you say it. (If you do, ignore what ever she says as you are walking away.)