What example am I teaching my kids by never working again?
[...]
I am not accomplishing anything. I have no defining contribution. What self esteem or work is there from not working?
Your poor mother reduces working, accomplishing something, making a contribution, valuing yourself all to just earning money. I don't know if it's possible to help her see that you do all those things without a paycheck.
Since you presumably don't spend your whole day watching soap operas, you must be setting an example to your kids of how to use your time meaningfully and how to appreciate the good things in life. Your actual activities are also teaching them lots of stuff: housekeeping, DIYing, riding a bike, grocery shopping, listening to music, and a thousand other things.
You know that your accomplishments and contributions, and hence your self-esteem, aren't measured in dollars. You know your mother and we don't, so you are the one who can judge whether there's any point to letting her keep reiterating her criticisms. Personally, having been in a somewhat analogous situation (though on a different topic), I tend to the view that berating you doesn't actually do her any good, and for her to repeatedly harass you is disrespectful.
LAL, I'm so sorry, this must be so hard to deal with.