Well, KT, I've been playing guitar for 35 years and just learned to play this past year. Now, how's that for learning to play midlife? I used to play a bit of piano, but haven't played in eons. My problem was that my hands don't stretch an octave and I was always having to maneuver things around.
You'll do fine, though. You have the wherewithal and the talent and just think how much your students will enjoy it! It's funny, I don't have any desire to play another instrument, except standup bass, except my guitars, but I want to be a really good geetar picker. So, perhaps, it is sorta the same.