But the Olsen twins don't look much her anywaymaybe there is a facial similarity, but Michelle is so much taller and fuller-figured than them that it would appear extremely jarring on set.
But forgetting that problem, Michelle probably wouldn't want to do the role (or dye her hair blond) anyway. She's usually selective about roles as it is, and is apparently involved in something that she is producing now.

Not at all. The whole point of Fuller House is to bring back the original cast. If they can't get the Olsens back, then they should just write Michelle off the show until they can.

Does she still act? Thought she was "producing" stuff now.

Interesting.