I figured those were nymphs, funny you mention Waterhouse, when I saw that I thought of "Hylas and the Nymphs"
I've always had a prejudice against Waterhouse from this painting, because the nymph turning her head looks like my 2nd oldest sister, who used to be very mean to me when I was a kid. This image of the painting I might add is a little off, I've seen higher quality images of it in the books where you can much better tell they are all redheads, and the exact same hue as my sister's hair.