I just bought my 7 year old daughter a
Wenger Junior 09.
It is a standard SAK size (85mm blade) but the main blade also locks. Their Junior line is interesting in that the main blade has a rounded tip instead of the traditional SAK drop point. In my case this made the knife a bit more Mom-friendly
.
This model also has the one tool I think is the most useful after the blade: the saw. I think this is especially true for kids who I find will try "sawing" with their main blade at some point anyway.
The other SAK's I personally recommend, generally speaking, are the
Victorinox Hiker and the
Wenger Ranger 78 (same toolset, different packages).
Personally, I'm not a fan of locking knives for new users. Typically you have to hit them "wrong" to close them, so keeping the threat of cut fingers will help them forge better knife habits. I've only ever cut myself on a locking blade.
This is a valid point, I had to teach my daughter to close the blade in two steps since it isn't possible to disengage the lock while also having all your fingers clear of the blade. It also means that the closing the saw (which doesn't lock) is done differently than closing the blade.