I like it. I think it's usable, and it's not hard to pronounce because of the flower.
I like
Amaryllis Blythe,
Amaryllis Coraline,
Amaryllis Gwen, and
Amaryllis Winifred.
I like
Hyacinth, mostly for a girl, but it would be too much in a sibset (unless one was a first name and one was a middle name).