If you don't trust your BIL at night with your DD while you are in the house, then he shouldn't even be at your house to begin with. But, you don't seem to have specific trust issue with him. He's just a male. From what you described, your feelings should also run to your husband, your father or ANY other male that you know, and any female for that matter. So, yes, I would say that you are wrong and over-protective. You could very well need counseling yourself. And stop watching Oprah and the like.