Would you think it over the top to remove a consistently misbehaving 2nd grader who thrives on attention from any situation that she can absorb it from? To be more specific, I mean even from family situations like meals or even doing chores. Just more or less complete isolation and minimal acknowledgement of existence. Premise it with something like, "since you have demonstrated a lack of desire to be a part of this family with your behavior, we have decided to grant your wish based on your actions". And see if things change in a week, and gradually start including her in family settings? Is this something you would approve of?