I could also add something in here about that whole "desire to play". I've said it a ton of times on the forums. My dad played guitar from the time I can remember. I picked up a "kid" guitar he had laying around quite a few times over the years... and Dad did make a couple attempts to teach me. BUT... I never really wanted to do the work to learn. I watch my four year old pick up her little guitar my husband bought for her. She doesn't want to "learn" she just wants to "play". It wasn't until a few weeks ago that I saw Dad couldn't (or maybe didn't want to... I'm not quite sure) play at the campfire anymore. I finally said to myself that it's time to learn! Now, there's a few guitars laying around the house. My daughter's tiny little guitar has steel strings on it...my son's has steel strings, my husband's does too. I built up some toughness playing these. Then... we went out and bought me a nylon string classical. Partially this is due to easier fretting, partially because of the sound, mostly because I liked it best. In the end tho... I've been playing it for a week and picked up the other steel string guitars in the house yesterday to see the difference now that I'm used to mine. NYLON is WAY easier to fret! I can't imagine a little person with those tender little fingers on a steel string.
I guess I'm saying... it may or may not be the right time for her to learn. It may get put in the closet until years down the road (in my case 20 some years!) until she's ready. And also... the strings might just be too hard for her to fret so a nylon could possibly be a better bet for someone that size. IF I was going to try to teach my little one, I'd be looking into nylon for her. Just a couple things to keep in mind. On the other hand... she might be ready willing and able to play... I wish you well and music in your family's life!!
The best thing my dad did for me... was have me as his "page turner"... I actually learned A LOT at a young age (when I could read of course), just by following along and knowing WHEN to turn the page in his music books... I have MANY happy memories of doing just that!
Art and beauty are in the eyes of the beholder.
What constitutes excellent music is in the ears of the listener.