DD5 has gone outside before. Luckily we have an alarm system. It beeps when a door opens. She sleepwalks often... I would say at least once a month. She has also always been a terrible sleeper...

DD9, who is HG, sleeps like a rock and has never had this issue.

I suspect DD5 is GT as well, we just haven't done testing with her yet.

So, is it a gifted thing? I don't know. I have one that does it, one that doesn't.