The only one that i truly like this nickname with (and i prefer the spelling Effie) would be Elizabeth.
I suppose Stephanie could be another. and Aoife...i love that name.
Elfrida, Efrona, Euphogenia but i wouldn't use those names as they are quite odd to the American ear..even if they are classic European names.
Another would be Eliza, akin to Elizabeth, but a bit redundant, unless of course the proper name is Eliza. which i do like.
I know Effy can be short for Ephraim for a boy.
Obsessed w/baby names, Military Wife & Mother of 4 (14 y/o son, 11 y/o son, 4 y/o daughter & 2 y/o son)