That is a really great point to bring up, JJ! I wondered about the brother too. I have a brother that I am very close to, talk every day, and he would have been my first phone call if my spouse had an accident. But if I truly didn't know what that accident was, I would tell him to standby and I'd let him know what was going on. The fact that her entire family was there in a heartbeat and she was falling all over the ground leads you to the very logical assumption that she KNEW much more than she is letting on.
I think during the parents' drive to Dunwoody, when the mom stated she was on the phone with Andrea for the whole drive trying to "calm her down," Andrea was acutally confiding in them what she had done or something to that effect. Maybe she truly panicked once the whole thing when down...boom, reality of it hit her that she would probably go to jail for the rest of her life for murder. That's why she was so "frantic" on the phone with her mom. Or maybe she was just putting on an act for her mom, too. I don't know. Maybe she was acting with her parents, too.