By the age of 6 months, Ruby clearly seemed to be emulating certain Ukulele behaviours, in addition to experimentation of her own.
Ukuleles are reasonably safe from babies, but you should NEVER LEAVE A NEWBORN UNATTENDED, ESPECIALLY if they have a ukulele.
Ruby may be imitating the things I do with a ukulele, or she may truly enjoy getting pretty sounds to come out of that ukulele. At any rate, it seems great that she gets a balance of listening to and creating nice sounds! And she sure loves to play it.
Sadly, UkeSchool is very young, and Baby Uke School is down the list of things to make. You can track the construction process in our construction blog.