Re: Length of time - That's why I said there's no reason to tell the powers that be that she's not actively pursuing it any further. As you said, she'll likely continue to play, even if she's not pushing to improve her technique. As long as she still sits down at the piano as little as once a month, she can accurately say, a year from now, "I've been playing piano for the past 10 years, and I recently picked up the guitar, as well."
Even if she's pressed and has to say she'd ONLY done formal lessons for 9 of those 10 years, I don't know how that could be considered dilettante. I mean, she only needs to commit to her chosen school for four years.
