I'm pretty sure that she has bar none done every stupid thing possible, the dumbest of which was to ever be gullible enough to trust a group that had Merle at is leadership core.
That is the problem with Andrea all series long: at her core, she's the biggest asshole of all in many ways.
Her greatest hits:
- She was dismissive of people she considered beneath her
- Tried to commit suicide, only to use that highly questionable act to play amateur head shrink by playing with Beth's own suicidal desires
- Took Shane's side on various issues / screwed him
- As Michonne put it, Andrea picked a warm bed over a friend
- Even after learning enough about the Governor to send any normal person running, she remained in Woodbury.
Anyone who dies as a result, their death will be on her head... & scumbag Merle, of course. If you are that careless in a world where people are hanging on by a thread, you deserve to pay
The only way she will learn a lesson is through Michonne--specifically, getting the beating of her life, then kicked out of Rick's group forever, although I doubt Andrea is going anywhere.