Hi mhl,
First, I very much enjoyed your daughter's performance. She plays with a wonderfully expressive lyricism and managed all the technical challenges of this piece very well. I was impressed with her phrasing, warm tone, effortless articulation, and fluency with Liszt's idiom.
Like some of the others here, let me say a few words about posture during performance. She does sway back and forth a lot, undoubtedly feeling the ebb and flow of the music. I'm old school, I guess, so I sit quite still, yet can elicit the same lyricism from the piano. There are a few instances where it is actually helpful, by exception, to move the trunk of the body forward or to lean back. When playing fff, moving forward can add some additional energy to the natural arm weight producing the big forte. If one has to play ppp, leaning back until the arms take on the sensation of floating in the air can help produce a delicately quiet sound. But constant swaying has not been shown to improve performance, although I do realize that many modern teachers are far more tolerant of this mannerism than those of the former generation. To me though, any mannerism is distracting. The role of the pianist is to be a transparent medium bringing the music to the audience, while serving the intentions of the composer through a sound interpretation of the work. To the extent that the performer is as unobtrusive as possible in the process, so much the better, for then the music stands more on its own merits, as it should.
I was watching her wrists too, and I believe someone else mentioned this point. She plays with very active wrists. The wrists must certainly be relaxed and flexible. But they are only one part of the entire playing apparatus of the arm. The trunk, actually, can have a role as impetus in initiating energy. The upper arm directs the lower arm. The lower arm, in concert with gravity, plays a huge role in tone production. The wrist, with the forearm, is important in differentiating various touches like legato, nonlegato, portato, staccato. It can also position the hand vertically and obliquely, and in turn, the fingers to best advantage, although if more "geography" must be covered across the keyboard, there again the upper arm will be directing those broad motions, while the wrist deals with smaller scope and angled movements.
What I see in your daughter's performance is a lot of unnecessary upward thrusts of the wrists, sometimes in isolation from the arms. True, if the pianist has to taper off a phrase ending, the upper arm will direct the lower arm to lift the wrist. But sometimes I see her raising the wrist first in order to raise the lower arm! I believe she would be better served by keeping a relaxed and flexible wrist, which she has achieved wonderfully, but at the same time aiming for a quieter wrist and hand. We sometimes call this "economy of motion". Motions at the keyboard need to be justified according to the effects they must produce. Needless or superfluous motions add no value to the quality of the performance, may even be a hinderance to execution, and will certainly call the audience's attention to them.
I mention these things as food for thought. But again, I want to congratulate her on this fine performance. She worked very hard on this piece to achieve an excellent result and deserves much credit.
Topic: Liszt "La Leggierezza"