I adore [name_f]Miriam[/name_f]! It’s gorgeous, familiar but unexpected and both the full name and the beautiful nickname [name_f]Miri[/name_f] sound equally good on a baby, an elderly woman and everything in between. I also agree that [name_u]Dean[/name_u] and [name_f]Miriam[/name_f] sound fantastic together and while some of your other ideas ([name_f]Daniela[/name_f] and [name_f]Vanessa[/name_f] especially) are lovely, in my opinion [name_f]Miriam[/name_f] just blows them all out of the water!
[name_f]Miriam[/name_f] is lovely! I used to not be a fan, but it has really grown on me in the last year or so (I met 2 lovely [name_f]Miriam[/name_f]'s) and I think it is a beautiful name with a beautiful meaning. [name_f]Miriam[/name_f] [name_f]Daphne[/name_f] is great too.
My favorite from your list is [name_f]Olivia[/name_f]. Other suggestions:
Merrivale
Mayfair
[name_f]Marian[/name_f]
[name_f]Marguerite[/name_f]
[name_f]Margaux[/name_f]
[name_f]Megan[/name_f]
[name_f]Maggie[/name_f]
[name_f]Agnes[/name_f]
[name_f]Marigold[/name_f]
[name_f]Primrose[/name_f]
[name_f]Marina[/name_f]
[name_f]Miranda[/name_f]
[name_f]Melody[/name_f]
[name_f]Oriana[/name_f]
[name_f]Stella[/name_f] [name_f]Maris[/name_f]
Rosinda
[name_f]Rosalind[/name_f]
[name_f]Rose[/name_f]
[name_f]Zara[/name_f]
Angelus
[name_f]Angelina[/name_f]
[name_f]Angelique[/name_f]
[name_f]Seraphina[/name_f]
Gabrielus
[name_f]Mae[/name_f]
Maebry
[name_f]Lucienne[/name_f]
[name_f]Elisabeth[/name_f]
All the best 
The one [name_f]Miriam[/name_f] I know has a brother called [name_u]Dean[/name_u]! Her sister is [name_f]Eleanor[/name_f] in case you are interested. [name_f]Miriam[/name_f] does get shortened to [name_f]Mim[/name_f] sometimes.