[name_m]Hi[/name_m] there.
Your grandmother’s name was Eleni?! That’s fun. I wish that my grandmothers’ had fun names like that to use as an honor name. 
Anyway, here are my thoughts on what you’ve got so far:
[name_f]Eleni[/name_f] Sophia-Sophia is really popular a fn, but doesn’t feel as much as a mn. [name_f]Eleni[/name_f] [name_f]Sophia[/name_f] is gorgeous.
[name_f]Eleni[/name_f] Phoebe-Phoebe a great name, but this is a bit too sing song-y for me.
[name_f]Eleni[/name_f] Mia-I love love the name [name_f]Mia[/name_f] (my kitty, [name_f]Mia[/name_f], is on my lap right now!), but it I feel like it’s too short as mn.
[name_f]Eleni[/name_f] Faye-This flows really well. I don’t love [name_f]Faye[/name_f], but not sure why.
Sorry for any repeats, but other ideas-
[name_f]Eleni[/name_f] [name_f]Azalea[/name_f]
[name_f]Eleni[/name_f] [name_f]Aurora[/name_f]
[name_f]Eleni[/name_f] [name_f]Aurelia[/name_f]
[name_f]Eleni[/name_f] [name_f]Beatrix[/name_f]
[name_f]Eleni[/name_f] [name_f]Callista[/name_f]
[name_f]Eleni[/name_f] [name_f]Clover[/name_f]
[name_f]Eleni[/name_f] [name_f]Freya[/name_f]
[name_f]Eleni[/name_f] [name_f]Juliet[/name_f]
[name_f]Eleni[/name_f] [name_f]Pearl[/name_f]
[name_f]Eleni[/name_f] [name_f]Theodora[/name_f]
[name_f]Eleni[/name_f] [name_f]Violet[/name_f]
[name_f]Hope[/name_f] this helps. 