My husband wants a girl name that is “tough but sweet”, isn’t that some sort of oxymoron? I guess what he means is a name for a girl who can hold her own, keep up with the boys, but still be sweet and polite. We prefer for the name to not be trendy or popular. We have a little boy named [name]Casper[/name] if that helps any. Thanks!
[name]Bryony[/name] is the first name that pops into my head with that description.
others:
[name]Bronwyn[/name]
[name]Amelia[/name]
[name]Audrey[/name]
[name]Briar[/name]
[name]Ramona[/name]
[name]Zoe[/name]
Hmm…not sure that I fullygrasp this concept. [name]Do[/name] you mean a substantial (i.e. “tough”) name that has cute nickname possibilities?
I’m thinking that maybe a feminization of a traditional male name might fit this “tough but sweet” category best:
[name]Josephine[/name]
[name]Georgia[/name]
[name]Simone[/name]
[name]Willa[/name]
[name]Petra[/name]
[name]Frances[/name]
[name]Harriet[/name]
[name]Samantha[/name]
[name]Martina[/name]
[name]Clementine[/name]
[name]Charlotte[/name]
Or a short, unfrilly name:
[name]Maude[/name]
[name]Wren[/name]
[name]Adele[/name]
[name]Blair[/name]
[name]Ruby[/name]
[name]Sage[/name]
[name]Ivy[/name]
Here are ideas - some or more on the tough side, and some are more on the sweet side. A strong nickname can help, though…
[name]Aurora[/name] ([name]Rory[/name])
[name]Beatrix[/name] ([name]Bea[/name])
[name]Charlotte[/name] ([name]Charlie[/name])
[name]Frances[/name] ([name]Frankie[/name])
[name]Gwendolen[/name] ([name]Gwen[/name])
[name]Juliet[/name] ([name]Jules[/name])
[name]Margaret[/name] ([name]Margo[/name])
[name]Phoebe[/name]
[name]Roxane[/name] ([name]Roxy[/name])
[name]Violet[/name] ([name]Vi[/name])
I think the toughest on this list are [name]Phoebe[/name] and [name]Roxane[/name], whereas the sweetest are [name]Aurora[/name], [name]Charlotte[/name], and [name]Violet[/name]. Names like [name]Gwendolen[/name] and [name]Juliet[/name] strike a happy medium, though…
[name]Lemon[/name] 
I second [name]Briony[/name] and [name]Bronwyn[/name] with [name]Casper[/name].
I think you need a name with tough or hard sounds but not overly so.
[name]Aurora[/name]
[name]Alexandra[/name]
[name]Maxine[/name]
[name]Georgia[/name]
[name]Juliet[/name]
[name]Gwen[/name]
[name]Gwendolyn[/name]
[name]Genevieve[/name]
[name]Jemima[/name]
[name]Jana[/name]
[name]Jacqueline[/name]
[name]Ginevra[/name]
[name]Annika[/name]
[name]Bridget[/name]
[name]Jillian[/name]
[name]Octavia[/name]
[name]Veronica[/name]
[name]Veda[/name]
[name]Victoria[/name]
I think these names would work well:
[name]Casper[/name] and [name]Briony[/name]
[name]Casper[/name] and [name]Bronwyn[/name]
[name]Casper[/name] and [name]Charlotte[/name]
[name]Casper[/name] and [name]Nora[/name]
[name]Casper[/name] and [name]Eleanora[/name]
[name]Casper[/name] and [name]Bridget[/name]
[name]Casper[/name] and [name]Juliet[/name]
[name]Casper[/name] and [name]Rosalind[/name] or [name]Rosaline[/name]
[name]Casper[/name] and [name]Odessa[/name]
I think [name]Beatrix[/name] fits the bill.
want to add [name]Harper[/name] and [name]Harlow[/name] to the list (:
I second [name]Bronwen[/name] (I’d use this spelling as In wales [name]Bronwyn[/name] is the male version) also [name]Briony[/name], [name]Juliet[/name] and [name]Georgia[/name] (although it perhaps is a bit off with [name]Casper[/name])
I think I understand what your husband means. Sweet but not cutesy? And not too frilly or floral either? The only name that really popped into my head was [name]Nina[/name]!
Definitely tough and like she could hold her own with her big bro and any other guys, but sweet as a button also without being cutsie like [name]Maisie[/name] for example.
Best of luck!
Names that came into my head
[name]Kate[/name]
[name]Jane[/name]
[name]Piper[/name]
[name]Anna[/name]
[name]Quinn[/name]
[name]Erin[/name]
[name]Georgia[/name]
[name]Nicola[/name]
[name]Jenna[/name]
[name]Samantha[/name]
[name]How[/name] about:
[name]Paige[/name]
[name]Blair[/name]
[name]Paige[/name] is my favorite.
Tough but sweet = no nonsense in my book.
No nonsense names:
[name]Jane[/name]
[name]Roxanne[/name]
[name]Eleanor[/name] (hello, [name]Roosevelt[/name]?)
[name]Abigail[/name]
[name]Martha[/name]
I am on a First Lady roll …
I think you already have a lot of great suggestions (particularly love the suggestion of [name]Ramona[/name]) and there are actually a lot of names that fit into this category. A couple that popped into my mind:
[name]Bernadette[/name]
[name]Veronica[/name]
[name]Rosalind[/name]
I second this! I have a cousin called [name]Nina[/name] who fits this description perfectly 
some other suggestions, sorry for repeats:
[name]Ivy[/name]
[name]Louise[/name]
[name]Una[/name]
[name]Corinne[/name]
[name]Esther[/name]
[name]Margo[/name]
[name]Tamsin[/name]
[name]Heidi[/name]
[name]Saffron[/name]
[name]Carys[/name]
[name]Anya[/name]
[name]Clara[/name]
[name]Roxanne[/name]
~[name]Elena[/name]
I agree with pp about [name]Beatrix[/name] sounds powerful, but feminie. Also, I love the nn [name]Bea[/name] which is strong and sweet
[name]Alexandra[/name], [name]Valentina[/name], [name]Andrea[/name] (aun-dray-uh), [name]Samantha[/name]
I love [name]Audrey[/name] with [name]Casper[/name]!
I think [name]Audrey[/name] is definitely a strong girls name, while also being very sweet
The first name that popped in my head for tough and sweet was
[name]Shelby[/name]
Other names I think fit:
[name]Amelia[/name]*
[name]Naomi[/name]
[name]Stella[/name]
[name]Lydia[/name]
[name]Vivian[/name]
[name]Scarlett[/name]
[name]Delilah[/name]
[name]Penelope[/name]
[name]Veronica[/name]
[name]Hazel[/name]
[name]Josie[/name]
[name]Phoebe[/name]
[name]Meredith[/name]
[name]Kali[/name]
[name]Vera[/name]
i too like [name]Casper[/name] & [name]Beatrix[/name] and [name]Casper[/name] & [name]Violet[/name]
here’s some that I think fit your description…
[name]Alice[/name]
[name]Ada[/name]
[name]Laurel[/name]
[name]Camilla[/name]
[name]Cleo[/name]
[name]Hannah[/name]
[name]Georgia[/name]
[name]Greta[/name] ([name]Love[/name] this w/ [name]Casper[/name])
[name]Honor[/name]
[name]Hazel[/name]
[name]Myra[/name]
[name]Maura[/name]
[name]Zoe[/name]