Ammersyn is interesting - like [name_m]Emerson[/name_m] meets [name_f]Amy[/name_f] meets [name_m]Amory[/name_m] meets Apsyn. [name_f]My[/name_f] big pause is that it sounds a bit like Amazon.
Some alternatives based on your list and on Ammersyn:
[name_f]Adalind[/name_f]
[name_f]Aveline[/name_f]
[name_f]Amity[/name_f]
[name_f]Abilene[/name_f]
[name_f]Amoret[/name_f]
[name_f]Amberly[/name_f]
[name_f]Amabel[/name_f]
[name_f]Amaris[/name_f]
[name_f]Amaryllis[/name_f]
[name_f]Amethyst[/name_f]