I know the disappointment of having your favorite name vetoed! Happened to me with both my kids, but happily they ended up with names I have no regrets about (and ditto for their dad!).
[name_f]Juno[/name_f]
[name_f]Clio[/name_f]
[name_f]Hera[/name_f]
These have all been suggested but came straight to mind when I read your post.
So did [name_f]Io[/name_f], which I think is very cool, but might be a hard sell to someone who had already vetoed [name_u]Hero[/name_u]. Maybe as a nickname to [name_f]Iona[/name_f]?
I have a real soft spot for “o” ending names for girls. [name_f]Juno[/name_f] and [name_f]Clio[/name_f] are my two favorites, but [name_f]Margot[/name_f] is also great (or [name_f]Margo[/name_f] if you want to go minimalist, or [name_f]Margaux[/name_f] if you want to go decidedly anti-minimalist French!).
Speaking of [name_u]French[/name_u], this was my first choice girls’ name (vetoed, alas!): [name_u]Léonie[/name_u], with [name_m]Leo[/name_m] as a nickname!
More from the Greek mythology side:
[name_f]Iris[/name_f]
[name_f]Daphne[/name_f]
[name_f]Leda[/name_f]
Also quite different, but has a similar spirit and some shared sounds: [name_u]Romy[/name_u]
Lastly, for the [name_m]Shakespeare[/name_m] side, these are some that are a bit more rare than say, [name_f]Juliet[/name_f], or [name_f]Beatrice[/name_f]:
[name_f]Nerissa[/name_f]
[name_f]Cordelia[/name_f] (Cora for short?)
[name_f]Ophelia[/name_f] (as suggested above)
Good luck! I think [name_f]Stefania[/name_f] makes a beautiful middle name and I’m sure it will mean so much to your husband and his family.
I’m very curious to hear what new ideas you have, because [name_u]Hero[/name_u] is so pretty!