[name_m]Hi[/name_m] 
an Italian here!
[name_f]Eleni[/name_f] [name_f]Carmella[/name_f] doesn’t flow as good as [name_f]Eleni[/name_f] [name_f]Grace[/name_f] or [name_f]Carmella[/name_f] [name_f]Grace[/name_f] in my opinion.
If you think your love for [name_f]Eleni[/name_f] could fade than I would go with [name_f]Carmella[/name_f] because at least it has a connection to your grandma, a deep meaning that will last forever. [name_u]Mel[/name_u], [name_f]Mela[/name_f] and [name_f]Mellie[/name_f] are cute nicknames imo.
However, if both your husband and you believe [name_f]Eleni[/name_f] is THE name for your daughter than name her [name_f]Eleni[/name_f]. [name_f]Eleni[/name_f] [name_f]Grace[/name_f] is gorgeous, [name_f]Eleni[/name_f] [name_f]Carmella[/name_f] doesn’t flow good and the names are just too different and have different vibes to go well with each other.
So, my picks are [name_f]Eleni[/name_f] [name_f]Grace[/name_f] or [name_f]Carmella[/name_f] [name_f]Grace[/name_f], depending on what you decide about [name_f]Eleni[/name_f]. Is a love that it’s going to last or you are not so sure?