The mother knows that the LAST thing you want to do when naming your son is wait for his father's say so. The next thing you know, the father's promised the baby to someone else because the lack of name means a riddling request.
Not that she doesn't trust the father to know that any riddling request should be refused. She just knows better than to tempt fate.
Which does mean I have to dig up a suitable fairy tale name when they are so short on them.