Which instrument should my child play?

The simple answer to this is "whatever instrument calls to your child's heart". There is no one 
instrument that is best to begin with. Young students will be guaranteed to give up in 6 months if they are not happy about the instrument they are learning. If your child is not sure what instrument to play, use the internet to search for clips of people playing all the different instruments so they can see and hear how different instruments sound. 

With all this considered the size of your child will have an impact on what instrument they 
can learn at the present moment. The following is a basic guide on what age children can 
learn an instrument, based on the average sized child.