Many of my new students ask me what the difference is between a fiddle and a violin. The instrument itself is basically the same, though sometimes the bridge is slightly flatter for a fiddle (mainly country fiddle) It is the style of playing that is different. Fiddlers hold their bows differently from classically trained violinists mainly becuase this creates a different kind of sound. I want to stress that that isn't true all the time. Often fidderls have some background in classical violin, rarely do violinists have any background in fiddle. All the same, I think it is easier for a violinists to fit in with fiddlers than the other way round.
Whatever you or your child want to do; classical music, Irish traditional, American country, Jazz, you don't know - any training that gives you the basics of scales, arpesggios, and listening skills, will help you to achieve your goal(s)