Even though almost everyone knows Martha Stewart, she is really no longer famous. Just because someone knows your name or your name is considered to be a household name, you really are no longer famous because you must be doing something to promote being famous.
Martha Stewart does a few things to keep her status. For example, she is sometimes a judge on the cooking show Chopped, but as far as creating her own show, she no longer does that. At 77 years old, she is probably ready to retire and will no longer have her own show or line of products.
Instead, she will simply do less and less and have fun retiring. Staying out of the public for the most part is what most people do after 75 years old.