Massively struggling to pick a girl's name!

I really like these:
Dorothy
Beatrix (Bea or Trixie)
Clara
Tabitha

But Maud is my favourite.

I like Tamara, Catherine (I knew a fabulous Kitty), Clara and Tabitha (though the only one that I knew went by the nickname Tabby).

Dorothy is still in the "great-aunt" category for me, as are Vera and Maud/ie, but they could grow on me.

Great list, like all of them except Dorothy and Margaret which sound very fuddy-duddy to me.

I especially like Daphne (but it’s quite trendy now), Tamara, Tabitha, Catherine and Maud.

ideas:
Caroline
Veronica
Miranda
Serena
Nadia
Justine
Maria

Similar names:
Lucinda, nn Lucy , Cindy
Henrietta , nn Etta,
Alexandra
Marnie
Maisie
Victoria
Elspeth
Esme
Jasmine
Cassandra
Jessica

Dorothy or Vera.
The other old lady names on your list are over used and the rest are bland.

Daphne -ok
Octavia. - reminds me ostrich (70s kids tv) but ok name
Tamara - quite like
Celine - not keen
Helena (Hel-ee-nuh) - quite like
Dorothy - love, or Dorothea
Vera - quite like
Beatrix (Bea or Trixie) - prefer Beatrice
Catherine (Kitty) - not keen
Clara - ok
Tabitha - love
Margaret (Maggie) - not keen
Penelope - live, quite popular where I live
Maud - not keen

I can see there’s a mix of traditional classic names, and less popular ones.

Maude is a nicer spelling
Tamara seems like an outlier on your list

how about Dorothea? With Thea, Dottie or Dolly as shortenings

The only ones I like are Daphne and Clara. Maud is awful!!

Have you looked at potential nicknames for all of the names to see if there are any you could compromise on if the other likes the nickname even if not in love with the first name?

Eg:
Daphne - Didi
Celine - Cece
Dorothy - Dotty
Vera - Vivvie
Penelope - Penny
Maud

If still no names can be agreed on some alternatives I think have a similar vibe to your list:
Mauve/ Mauva
Elise
Constance (Connie)
Jemima
Clementine (Clemmie)
Cora
Matilda (Tilly or Tildy)

All of the names are lovely. Personal choice is understandably diferent for two people.

My favourite names from your list:
Catherine
Clara
Helena
Maud
Octavia
Beatrix
Margaret

Names I quite like:
Tamara
Celine
Vera
Penelope

Names I wouldn't use:
Tabitha
Daphne
Dorothy

Others ...
Claire
Mary

We know a Penelope who is shortened to Nella, which is super cute. So it doesn’t have to be Penny.

Love Clara. Tabitha also nice.

Favourites

Beatrix
Clara
Margaret (Maggie)
Penelope

These are all really lovely names and I'd pick one of those.

Daphne - ok but a bit soft. Daffy isn't a great nickname.
Octavia - Dislike. Long name with no good nickname potential. Might make me assume she's the 8th child.
Tamara - It's fine. How do you feel about Tammy?
Celine - It's hard to not hear Dion but yes it's fine. CeCe as nickname?
Helena (Hel-ee-nuh) Nice but you will always have pronunciation issues. I think I prefer Hel-e-na. With your pronunciation it's quite a long name, have you got a nickname?
Dorothy - It's ok. Dotty very cute when little but I'm not sure about being a teenage/ adult Dorothy.
Vera - Dislike.
Catherine (Kitty) - Nice. Not a favourite but works really well. Katherine if sure on Kitty?
Tabitha - Very nice.
Maud - Bit like Dorothy, it's ok but not great. Not sure I'd like it to be my name.

Daphne - no
Octavia - Pipkins! No.
Tamara - ok
Celine - no
Helena (Hel-ee-nuh) - no
Dorothy - no
Vera - no
Beatrix (Bea or Trixie) - Prefer Beatrice
Catherine (Kitty) - ok
Clara - no
Tabitha - ok
Margaret (Maggie) - no
Penelope - lovely
Maud - ok

Other names

Louise
Eloise
Erin
Persephone

All really nice but Tabitha, Penelope, Margaret and Catherine stand out for me.
Love the diminutives Penny and Maggie particularly.

Be aware Maudie may become ‘muddy’ at school.

The names seem to be very old fashioned / very boring or a bit ‘out there’ but not in a good way!

Clara is my fave.

Love Daphne, Dorothy, Clara, Helena, Tabitha

Celine - lovely name
Helena (Hel-ee-nuh) - also a nice name
Dorothy - NN Dot or Dotty would be cute as a child
Beatrix (Bea) - lovely name, but not Trixie
Catherine (Kitty) - great name
Clara - nice
Tabitha - lovely
Penelope - nice
Maud - think this might actually be pretty cool! I can imagine a cute toddler Maud, and a young women called Maud

We have a long and unusual surname.

I love your list but because of our surname we stuck to really simply names with no spelling/pronunciation variances:

Emma
Anna
Alice
Rose
Poppy

If you like Maud, might you both like Marnie?

Daphne - ok
Octavia - too “much” for me as a full name, and I don’t like the nn options
Tamara - ok, Tammy is a bit dated but she could go by Mara, which I like
Celine - a bit dated, she’ll get sick of being sung Celine Dion songs
Helena (Hel-ee-nuh) - nice but pronunciation variations put me off, never heard it said this way
Dorothy - quite nice, I like Dory but not Dot / Dotty
Vera - no, too frumpy / old fashioned
Beatrix (Bea or Trixie) - prefer Beatrice, I like Bea
Catherine (Kitty) - nice
Clara - love this - if I had another dd this would be on my list
Tabitha - like, but dislike Tabby
Margaret (Maggie) - nice
Penelope - love, and love Penny / Nell / Polly / Poppy nn options
Maud - no, very frumpy to me - almost comically so

I would pick Clara, Penelope, Margaret (Maggie) or Katherine (Kitty).

Daphne - No
Octavia - Skoda car
Tamara - See ya Tamara!
Celine - Naff, like you’re copying the designer bags
Helena (Hel-ee-nuh) - Too like Helen and bit dated.
Dorothy - Awful
Vera - truly truly awful
Beatrix (Bea or Trixie) - Not keen.
Catherine (Kitty) - Boring
Clara - Love
Tabitha - Love
Margaret (Maggie) - Dreadful
Penelope - Nice but I hate Penny
Maud - Fucking awful.

Daphne - too close to daphnia (water flea)
Octavia - car
Tamara - ok
Celine - medication
Helena (Hel-ee-nuh) -really like
Dorothy - ok
Vera - ok
Beatrix (Bea or Trixie) - really like
Catherine (Kitty) - Catherine like, kitty awful
Clara- really like
Tabitha - a cat or a watch's name
Margaret (Maggie) - ok
Penelope - thunderbirds
Maud - really dowdy

I have a girl called Mackenzie (Kenzie for short) who massively suits her name! Couldn’t imagine her being called anything else.
My other options were Hannah or Alexandra (the latter not going well with surname). I’ve also since decided I like Martha and Elise

I like
Daphne
Celine
Catherine (Kitty)
Clara
Maud

Martha is really nice. I also like Lydia, both sound like cool women in NYC in the 1970's.