I like all of these, too, but only as nn's and not formal names.
Millie - I like
Millicent,
Camilla,
Camille, and
Amelia Ellie - I like it for
Eleanor or
Eleanora, but it's a little too popular for me (even in the U.S.)
Nell - I like it as a nn for
Helena or
Penelope.
Effie - I'm not crazy about
Euphemia, though
Effie is awfully cute. Not sure what else it could be a nn for. Maybe the initials F.E.? :b
Mamie - Cute, though not a huge favorite.
Maisie - I adore this. It's my favorite nn for
Margaret and also
Mairead. This is the one I'd be most likely to use as a name on its own, though. It seems a little less nickname-y than the others to me for some reason (and I don't love
Margaret or
Mairead as much as I do
Maisie).
Minnie - I also wish it wasn't so associated with
Minnie Mouse. :( I like it best as a nn for
Araminta.
Fan /
Fanny -
Fanny's cute but unusable, imo. :-/ I don't like Fan at all.
Bridie - Just ok.
Brigid is the only other one I can think of.
Nan - Cute, but not a huge favorite.