Michelle was in the White House for 8 years. She's a Harvard Law graduate with a career in the public sector or through nonprofits. She is no stranger to either politics, social issues, or advocacy.
So, yeah. One could be a lot less qualified than this. If she wanted to be more qualified, she should first run for Senator. But she has nontrivial qualifications, if not an expansive resume in politics (strangely, that's become a liability. What a world), and an obvious political aptitude.
But, it's quite moot. There's no indication she has much interest in politics, yet. That could change.