How about Rosalin (combo of Rose and Catherine; nicknames could include Rosie, Rose, Rosa, Rosalie) or Lilliania (combo of Lily and Anya; nicknames include Lil, Lily, Liana, Lia)? Lynnea (pronounced "lyn-ay-ah"; nicknames could be Lynn, Lynné, Nea) ? Caitlin (form of Catherine; nicknames could be Cait, Caity)? Agnes (Aggie, Ness, Nessie)?
If you haven't found a name that just struck you as "the one", its probably because you aren't allowing yourself to feel the name, instead of analyzing it. Really, its important to feel a name, since its going to be on a child, not a robot. I don't think you'll ever find the right name if you never just feel for it.
Whoa, you're picky!
Abigail (Abbie, Gabi, Gia, Gibby, Ibby, Laila, Libby)
Amabel (Amy, Bella, Bea, Ella, Mabel)
Aurelia (Aura, Elia, Lia)
Aurora (Aura, Ora, Roo, Rory)
Cecily (Cece, Cilly)
Cordelia (Cora, Cordy, Delia, Elia, Lia)
Cornelia (Cora, Elia, Lia, Nell)
Cressida (Cressie, Essie, Ida)
Delphine (Delphie, Phinee, Phee)
Eleanor (Ella, Ellie, Elea, Lea, Lena, Lora, Nell, Nora)
Eugenia (Genie, Nia)
Felicity ( Flick, Fliss, Lissy, Letty, Tilly)
Florence (Fee, Flora, Flossie, Lorrie, Rena, Florrie)
Gwendolen (Della, Dolly, Elen, Gwen, Lola, Wendy)
Jemima (Emmy, Ima, Jem, Mimi)
Josephine (Effie, Fee, Fina, Jo, Josie, Posy, Sophie)
Lavinia (Lavy, Vinnie)
Letitia (Etty, Letty, Tia, Titia)
Lucille (Lucy, Cilla)
Matilda ( Mai, Mattie, Milla, Millie, Tally, Tilda, Tilly)
Penelope ( Ellie, Lola, Nell, Penny, Polly, Poppy)
Perdita (Dita, Perdy)
Rosemary (Rose, Rosie… Roma?)
I kind of doubt our ability to help... if you have such strong criteria I think it is only you who can find the perfect name, if one exists.
I like the names on your list... maybe look at longer forms of Rose and Lily.
Rosalie is my personal favourite and to me it fits for you.
Liliana is my favourite Lily name, but the ana doesn't fit... how about Lillian, Lilia?
Because your "rules" are so personal, what may be "soccer mom" to you could possibly be "elegant and timeless to me". So I don't know if I'm much help!
I hope you find the perfect name for you, maybe broaden your horizons a little and it might find you!
Good Luck, sorry I wasn't much help!
P.S. Ottillie, nice suggestions!
I don't think any name could exactly fit that criteria, but here are some suggestions.
Eleanor - Ellie, Nora, Lea
Victoria - Vicki, Tori, Ria
Clara - Clare, Lara
Rebecca - Becca, Becky
Olivia - Ollie, Livi (might be too popular?)
Virginia - Nia, Ginny
Matilda - Mattie, Tillie
Lucinda - Lucy, Cindy
Adelaide - Addie, Delly
Alexandra - Ali, Alexa, Sandra
Camilla - Cammie, Millie, Milla
Caroline - Cara, Carol, Callie
Cordelia - Cori, Delia
Emmelyn/Emmalyn - Emmy, Emma, Lyn
Isadora - Izzy, Dora