Your story mirrors mine. My daughter did the same thing. I'm disappointed, too because she has perfect pitch and can play anything-- if she wants to. My strategy is to sit around and play and make it look so fun that she'll want to do it. Either that or play her bass instead of mine all the time so she gets jealous. Good luck!
My seven year old started asking for music lessions about 6 months ago. She wanted me to take lessions with her so I bought a bass and we started playing. I really am enjoying it and wish i would have started earlier. She was really excited all through the process of buying her guitar, she was excited in the car all the way to the lession. Then, as soon as she played one note it was over. Now she whines every time I ask if she wants to practice. I don't mind that she doesn't want to play, that doesn't bother me, it's the fact that she refuses to try before quitting. Is this a common thing with kids? I've never seen her so excited before, then it's like someone flipped a switch in her head. Do i push her to play hoping that when she learns a song it takes off, or do I back off, not say another word, and see what happens. I don't want to send the wrong message.
I quickly switched to a different instrument, but continued with music lessons through high school.