My four older girls are not babies, they are 10. 12. 14 and 16 years old, but they have been playing guitar and writing music for a little over 3 years. They recently formed a band and decided that this is what they want to pursue. We finally have some of their work up on YouTube. You can check out their music here. They have not had any formal training. One of my girls had 6 weeks of lessons, which went no where, so we stopped. My dad showed my girls some chords and between chords, YouTube and a few tips from my dad every once in awhile this is where they are.
http://www.youtube.com/user/DavidaBand?ob=0&feature=results_main