People unfamiliar with the instrument think that the "real" part of playing a violin is the left hand running on the board of the violin (where the strings are pressed by the fingers). Just to let those people know, the bow plays a more important role in producing a good sound than the fingers on the strings! The main factor involved in the quality of the bow is the flexibility (bounciness) of the wood. While initially it is not of utmost importance to have a good quality bow, when your child starts practicing different techniques (portato, spiccato, etc) the quality of the bow will play a major role in producing the proper sound. Good bows are expensive so be ready to dash out several hundred (or thousands!) of dollars for a high quality bow.