Your wife sounds insecure. Did she have a previous relationship that dissolved due to cheating? Or maybe her parents cheated?
Please don't take offense to this, but did you two get together while one of you was married or in a serious relationship with another? Have you ever cheated, and she knows about it? Has she ever cheated and you know about it?
Sorry if this all sounds nosy, I'm trying to understand why she might be so insecure as to be jealous of another woman even looking at you.
Her insecurity may be a bottomless pit, and no matter what you do she may not get over it without some outside help. If you can determine where her insecurity springs from, you might want to discuss it with her. If this does not help, seek counseling.
