Sorry, I went back and re-read your original post. I didn't get that
Edna / Millay would be mns only. How about:
Rosamund EdnaWinifred Edna (Too much "ed" perhaps, but stylistically they match, to me.)
Beatrice /
Beatrix EdnaGuinevere EdnaIngrid EdnaWilhelmina Edna (
Mina)
Muriel Edna (This one has the best flow, to me)
Vivien EdnaOttoline /
Ottilie EdnaBernadette EdnaConstance EdnaMiriam Edna (Miri,
Mimi, Mim)
Lenore EdnaNell Edna
Saskia Millay
Astrid Millay
Iris Millay
Sylvia Millay (my favorite of these, although
Cornelia Millay is terrific too)
Jacintha Millay
Ailsa Millay
Henrietta Millay (
Harriet /
Hattie /
Hettie /
Etta /
Ettie)
Georgina Millay
Eugenia Millay (Genia,
Genie)
Aurelia Millay
Verity Millay
Constance Millay
Anna Millay (
Anouk,
Nan)
Millay almost sounds like "milady (= my lady)." Cute. I only included possible nns, because sometimes they can appeal more than the full name to a partner who needs convincing.
Good luck and happy memorizing!