Using a slightly darker shade of green (and another layer mask to hide anything that popped out of her eye), I painted her eyes on a new layer set to 'overlay'.
Using the 'soft light' setting of the layer, the same green color as her hair was applied to her lips. I decreased the opacity of this layer to 50%, giving it less of a 'painted on' look.
Using Select > Color Range and after quite some fumbling with the eyedropper tool, I managed to select everything green, inverse the selection and desaturate. (First time I used the Select > Color Range option as well...)