This is a perfect pairing of instruments for a more experienced player and a less experienced player to learn together.
The 10-Note kalimba has wider tines with more space in between, making it easier to play. The biggest advantage of the 10-Note however, is that it is conceptually easier. With five tines on the left and five tines on the right, it really feels as if you could understand this instrument and learn to play it well. And of course, you can. That said, there is actually a lot you can do with the 10-Note kalimba, and its tone is lovely. It is also an instrument that you can play for several years and still advance on it.
And those 10 notes just happen to match the lower (central) 10 notes of the 17-Note kalimba. They are painted the same way.
So, parent could play the 17-Note and child could play the 10-Note. Parent can teach child on the lower 10 notes of their instrument. Then when child gets it, parent can go and play the melody an octave higher, and the two together can make some really beautiful music.
Of course, the real magic happens when child graduates to the 17-Note and then starts to teach the parent how to play.