One issue is that the better the kids play, the more the piano teacher wants them to practice. The good news is that both kids will go to the piano on their own and improvise and mess around. And with more lessons, the better the improvisation sounds.
That is so true! DS9 over here practices 45-60 minutes a day. If someone would have told me a couple years ago he'd be doing this willingly, I would have laughed. He sits down all the time and improvises, reads music, figures out sound by ear. He also took a theory class this fall which was great. Very challenging. It involved things like inventing left hands to go to right hands in different patterns. And transposing short tunes to different keys.
DD5 usually practices violin around 20 minutes a day.
I started really small 5-10 minutes a day. DS at 5 ramped up pretty fast. DD starting at 4 on violin was a little slower. Now that I've started a kid on piano and violin, violin seems MUCH slower and harder initially. So many different things to think about to even get a half way decent sound out of a little violin.
She can play a bunch of folk songs and jingle bells, so she's very happy with that. I'm a little sick of it though!