I like your ideas for your daughter - I think studying abstract art is an excellent place to start.
What about suggesting that she try communicating an idea, rather than duplicating an image in her head? For example, she could draw "confusion" or "bliss" or something like that. Then the task becomes about representing the emotion, and this might help to free her.
Or... you could suggest she try illustration - specifically for kids' books, again as a way to loosen her up a bit. Have her look through some artfully illustrated kids' books, and point out how the story's spirit and emotion is conveyed in a childlike and whimsical fashion (rather than being aged and sophisticated the way that adult illustrations are).
This is interesting to me... there's a parallel here with my daughter's piano. She started at 7, and was a natural composer. At her first piano recital, after having been in lessons for only 3 months, she played a 3-part original composition, two handed, in D-minor. She also played her own two handed arrangement of Ode to Joy. Between lessons she'd sit at the piano and noodle away, creating piece after piece.
She's now 9, and not only has her playing progress stalled, but sadly she no longer creates her own music. It's as if as she's gotten older she's become more self-critical and aware. I almost wonder if lessons have hurt the composer in her by applying "rules" to the music. I think we're going to take a break from lessons (her teacher is leaving the country for a year - we may just refrain from finding a replacement). Maybe this way she can rediscover the joy of following her own ear? Here's hoping
Sometimes I think that stagnation can be a normal glitch in their development... but on the other hand, do you ever wonder if they've lost their magic for good? It can be tough to know what the right thing to do is.
I do know that with writing (my parallel) sometimes when you're blocked, you just have to keep writing. Write, write, write. Write through the junk until you get back to the good stuff. Kind of like getting the car out of the muddy ditch and back onto the smooth road. Maybe our daughters just have to do that... persevere through the glitches...
