SatcJip, I will not get heavy into music learning psychology, but just let me say that the hour I spent yesterday (and the hours I’ve spent for the past week) learning a very difficult contemporary work was definitely a “chore”! Not that the end result will be a chore when working in the full ensemble, but right now, I can think of many things I’d rather do! Practice is a part of life for us professionals and serious students, but we don’t often sit around “enjoying our music” as some have suggested to me. I agree that it is fulfilling to see your skills grow and to learn new rep, but this does not come without work and, sometimes, at the expense of other interests. For professionals, practice is part of our work - our job duties, if you like. If I couldn’t stand doing it, I’d be in another field.
I definitely agree with the suggestions that continuing piano is not worth a battle fought by the OP. If it comes to that, I also would allow the student to make her own decision.