It’s kind of possible, yes. Basically it would have to be a coordinated effort at the convention to elect her as the party’s candidate. That makes it incredibly unlikely. Also, the person elected at the convention still has to accept it.
Since she was FLOTUS, she hasn’t shown much interest in participating in the dirty politics of governing. Instead, she quickly said she wanted to focus on social issues. That made me kind of sad because she’s incredibly intelligent and I think she would be a talented political leader. She just doesn’t seem interested in that.