It is important for your child to have a guitar of a suitable size.

Either ½ or ¾ size are generally best. 1/2 size is great for younger kids with smaller hands. 3/4 would generally be better for P6/P7. 

Gear 4 Music offer a good selection. The packs with some picks and a bag are useful. We will not be using any of the books that come with the guitars. 

www.gear4music.com/Acoustic_Guitars/Gear4music-Kids-Guitars

If possible, it is advisable to visit a dedicated music shop where your child can try both sizes to see which they are most comfortable with.

A passed down full size acoustic guitar is unsuitable as your child will most likely not be able to see over the top of it!

A nylon strung guitar is recommended for children who
might be a bit averse to pain - steel strings sound better
​but hurt little fingers :-)