Ada - Like this. It's a nice change from Ava and works well in a lot of countries.
Alice - Nice, but a bit overdone at the moment.
Edith - I like this with Edie as a nickname. 
Elena - Like this one, but will have pronunciation issues, be warned! My husband is Scandinavian and where he is this is pronounced Eh-LEE-nah (similar to Alina), but I'd heard it pronounced Eh-LAY-nah and Eh-LEH-nah (like Eleanor) before.
Emma - Sweet, but overdone too.
Frances - Don't like.
Francesca - Don't like.
Hazel - Love this one.
Julia - Love this too.
Margaret - Don't like this.
Maria - Don't like this. It's outdated.
Martha - Love this, still trying to convince my husband to go for this one.
May - Like this.
Nora - Like this too.
Pearl - Very harsh sounding as a first name, IMO. But it makes a nice middle name.
Rosa - Don't like this.
Ruth - Quite nice.
Valerie - Don't like this.
Violet - Lovely, but very popular.
How do you feel about Olive?