I used to sit in the family enclosure until last summer (when they kicked out any families who no-longer had a young child in tow.)
It's a more then suitable place for the youngsters, there are regularly children about 4 years of age in that section and although it is busy the atmosphere is friendly yet nicely partisan.
For the Yeovil cup game though it will be quiet, no more the 16k I would say so you will be able to get tickets there easily and see how he copes.