I would say your palette is going too far into royal blue, making it look a little garish. If you added one more shade to the palette,a blue/grey tone.
YOu would be able to use this for your highlight, and it would make the skirt less saturated in colour, without losing the blue.
I did a quick reline just to show how the new tone could work.

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The blue still looks very similar, but richer. ( also bubbled out the skirt a bit more, at the moment the folds youve done work against the outline, as the dont follow the curve of thee matirial, but by curving them in at the base will make it look better for you.