I suppose it's normal for this age. It really is about "me" and "mine", but can I tell you just how crazy this actually makes me? My favorite under my breath grumbling to this selfish bratty remark is, "you're so lucky you're mine". Then another side of me occasionally finds it cute that she is differentiating between what is "mine" and "yours". At least she's doesn't try to keep what doesn't belong to her even if it seems she's rather territorial about what's hers.