Not preggo but we are going to start TTC again in the next few months. We have a son Gavin Michael about to turn 2. Last name starts with a B and rhymes with Tyler. The lists are sort-of-ish in the order I like them.
For Girls:
Vera
Sylvia/Sylvie
Phoebe (but is it out since my LN starts with B?)
Stella
Amelia (popular but I don't know any IRL)
Fiona
Louisa
Nora
Alice
Margot nn Maggie
Boys:
Nolan
Simon
Oscar (is the -er ending a no-no with our -er last name?)
Elliott (weird if we are not religious?)
Owen
Miles/Milo (does the long "i" sound funny with our last name which rhymes with Tyler?)
Declan
Jude
Felix
Favorites? Do they work with Gavin? Suggestions?

DS born Oct. '11
TTC #2 with PCOS since Nov. '13
Dx: Low Progesterone (3.3) on 8/12/14
Waiting for RE appointment on 10/28/14
Surprise BFP on cycle 12 -- 10/19/14!
EDD July 1, 2015
Re: Critique my lists please?
From your girls' list, I like Vera, Stella, Louisa, Alice and Margot. Margot would be my favorite, except that I don't really "get" using Maggie as a NN (they're both two syllables, so it's not like it "saves" any time, and they're both already NNs for Margaret).
From your boys' list, I like Oscar, Declan, Miles, Jude and Felix. Oscar is probably my favorite, but I really like all of them.
I'm a religious person, and fairly "up" on religious things (even those not pertaining to my religion), but I don't know the religious connection with Elliot. I think of poet T.S. Eliot.
DS born Oct. '11
TTC #2 with PCOS since Nov. '13
Dx: Low Progesterone (3.3) on 8/12/14
Waiting for RE appointment on 10/28/14
Surprise BFP on cycle 12 -- 10/19/14!
EDD July 1, 2015
DS born Oct. '11
TTC #2 with PCOS since Nov. '13
Dx: Low Progesterone (3.3) on 8/12/14
Waiting for RE appointment on 10/28/14
Surprise BFP on cycle 12 -- 10/19/14!
EDD July 1, 2015
Ah, gotcha. I wouldn't worry about the meaning. Almost nobody knows what names mean without looking them up, and lots of "mainstream" names have religious meanings (like Elizabeth, James, Abigail, etc.).
You might consider Magdelen/Magdelene/Magdelena NN Maggie.
ETA: Admittedly, Magdalene is a pretty religious name...
My favorites, in this order
Margot (I personally dislike Maggie, but there's nothing "wrong" with it.)
Nora
Alice
Louisa
-----------------
Jude
Miles
I like Phoebe, Louisa, Nora, and Alice
I like Simon, Elliott, Miles, Jude, and Felix. I'm religious and saw more of a religious theme with Jude over Elliott (I see that as a last name as FN situation)
Josephine?
Olivia?
I love the names Nolan and Jude although I'm hearing Jude quite a bit lately. I also really like Declan.
Nora is the only girl name that jumps out at me from your list. I'm not really sure how I feel about it paired with Gavin though. Nothing wrong with them but it just seems like 2 different styles.
I also think Jude is a great name, it's been on our boy list both times.
DS born Oct. '11
TTC #2 with PCOS since Nov. '13
Dx: Low Progesterone (3.3) on 8/12/14
Waiting for RE appointment on 10/28/14
Surprise BFP on cycle 12 -- 10/19/14!
EDD July 1, 2015