I've been teaching Guitar for many decades, and it took a couple of them for me to figure out that if the child begins on a Baritone Ukulele, it is small enough to fit their little hands & body. It is tuned to the same notes as the 1st, 2nd, 3rd, & 4th strings of a Guitar,[D-G-B-E from low to high] and it has nylon strings to boot. Since it only has four strings, the neck is much more comfortable for little fingers & hands. Anyone who plays Guitar can help her play simplified chords--just like fingering an open chord except only use the fingers you'd use for the 1st, 2nd, 3rd & 4th strings. One can get a decent Baritone Ukulele for about $50-$60 at most any Music store which carries a variety of Musical Instruments. Then as the child grows, their fingers will be ready for a Guitar, & the parents have had time to save up $$ for a good one.