When the guitar is really big they end up spending more time wrestling them than playing them and you don’t want the learning process to be frustrating for them. I would recommend the Parlor as it will have a bigger sound but yet be small enough for them to get their arms around. Here’s a link to see it: http://www.zagerguitar.com/guitars/parlorsizemahogany
You can see all of our sizes with measurements on this page: http://zagerguitar.com/sizes/
If the child already has a guitar, say if they are a little older, go by what they play now and if they are ready to upgrade in size. Bottom line you don’t want to overwhelm any beginner, especially a younger player, because it hinders them from wanting to practice and get over the initial hump until they can play “real” songs and music and enjoy the playing. I’d say go off of what he has already played and held and what has and hasn’t been comfortable for him so far. That should help decide if he wants a smaller guitar or full size.
