I need a “D” name in there somewhere to honor a family member…
Here are the top choices right now:
[name]Amelia[/name] [name]Darcy[/name] (nn probably [name]Millie[/name])
[name]Olivia[/name] [name]Darcy[/name]
[name]Dahlia[/name] [name]Jane[/name]
[name]Margaret[/name] [name]Dahlia[/name] (nn probably [name]Maggie[/name])
[name]Charles[/name] [name]Dexter[/name] (nn [name]Charlie[/name])
[name]Thomas[/name] [name]Dexter[/name]
[name]William[/name] [name]Dashiell[/name]
[name]Amelia[/name] [name]Darcy[/name]: I think this is pretty. 
Some more:
[name]Amelia[/name] [name]Daphne[/name]
[name]Amelia[/name] [name]Daisy[/name]
[name]Olivia[/name] [name]Darcy[/name]: I think it’s pretty, but [name]Olivia[/name] is so popular these days…
[name]Dahlia[/name] [name]Jane[/name]: Oh my gosh! I [name]LOVE[/name] this! This is my favorite from your list!
[name]Margaret[/name] [name]Dahlia[/name] (nn probably [name]Maggie[/name]): I love both names, but not together because of the flow.
More ideas:
[name]Amelia[/name] [name]Daphne[/name]
[name]Amelia[/name] [name]Daisy[/name]
[name]Daphne[/name] [name]Jane[/name]
[name]Diana[/name] [name]Jane[/name]
[name]Charles[/name] [name]Dexter[/name] (nn [name]Charlie[/name]): I [name]LOVE[/name] this! (I like [name]Dexter[/name] [name]Charles[/name], too!)
[name]Thomas[/name] [name]Dexter[/name]: I like this, too…
[name]William[/name] [name]Dashiell[/name]: I [name]LOVE[/name] this! I’m voting for this, with [name]Charles[/name] [name]Dexter[/name] in second place.
I really, really love your list, especially [name]Dahlia[/name] [name]Jane[/name], [name]Charles[/name] [name]Dexter[/name], and [name]William[/name] [name]Dashiell[/name].
Best wishes to you!
All of these are pretty! I love [name]Amelia[/name], [name]Dahlia[/name], and [name]Margaret[/name]. [name]Olivia[/name] is lovely, but really popular.
[name]Margaret[/name] [name]Dahlia[/name] is also very nice. I think with [name]Jacob[/name], I like [name]Amelia[/name] and [name]Margaret[/name] best.
Here are some other D names to think about:
[name]Daphne[/name]
[name]Delia[/name]
[name]Delilah[/name]
[name]Diana[/name]
[name]Delphine[/name]/ [name]Delfina[/name]
[name]Deirdre[/name]
[name]Daria[/name]
[name]Daisy[/name]
[name]Delia[/name] [name]Jane[/name]
[name]Amelia[/name] [name]Daisy[/name]
[name]Margaret[/name] [name]Delphine[/name]
[name]Daphne[/name] [name]Olivia[/name]
Out of [name]Charles[/name], [name]Thomas[/name], and [name]William[/name], I think I like [name]William[/name] best, though all are nice.
[name]David[/name]
[name]Daniel[/name]
[name]Damian[/name]
I love [name]Darcy[/name] for a middle name.
I agree [name]Amelia[/name] [name]Darcy[/name] is very pretty.
Also [name]Charles[/name] with [name]Dexter[/name] works great. I love love [name]Dexter[/name] and [name]Daxter[/name].
You have some great combos. I’m only adding more for variety and it’s fun
Let see -
[name]Amelia[/name] [name]Delaney[/name]
[name]Amelia[/name] [name]Danae[/name]
[name]Olivia[/name] [name]Dorian[/name]
[name]Margaret[/name] [name]Danica[/name]
[name]Margaret[/name] [name]Dean[/name] - a boys name that might work for a girl.
[name]Margaret[/name] [name]Day[/name] or [name]Margaret[/name] [name]Dae[/name] - I like this one.
[name]Charles[/name] [name]Donovan[/name]
[name]Charles[/name] [name]Dorian[/name]
[name]Charles[/name] [name]Dean[/name]
[name]Thomas[/name] [name]Damian[/name]
[name]Thomas[/name] [name]Dillon[/name]
[name]Thomas[/name] [name]Dryden[/name]
[name]Thomas[/name] [name]Devin[/name]
[name]William[/name] [name]Drake[/name]
[name]William[/name] [name]Dominic[/name]
[name]William[/name] [name]Dayton[/name]
[name]Margaret[/name] [name]Dahlia[/name] & [name]Thomas[/name] [name]Dexter[/name] are gorgeous!
I think [name]Margaret[/name] [name]Dahlia[/name] goes the best with [name]Jacob[/name]. Anyone of your male options would fit just fine, in my opinion.
[name]Amelia[/name] [name]Darcy[/name] Sounds very pretty but I would use the nn of [name]Mia[/name] or [name]Mimi[/name]
[name]Olivia[/name] [name]Darcy[/name] Same as above [name]Olivia[/name] more popular
[name]Dahlia[/name] [name]Jane[/name] [name]How[/name] do you pronounce [name]Dahlia[/name]? Where we live it is said [name]Dale[/name] ya not Dah lee ah. If second option it flows well and sounds pretty.
[name]Margaret[/name] [name]Dahlia[/name] (nn probably [name]Maggie[/name]) I would make this [name]Margot[/name] [name]Dahlia[/name] much softer and prettier
[name]Charles[/name] [name]Dexter[/name] (nn [name]Charlie[/name]) [name]Charles[/name] and [name]Charlie[/name] are gorgeous but [name]Dexter[/name] has the nerdy vibe to it.
[name]Thomas[/name] [name]Dexter[/name] [name]Thomas[/name] a good traditional name
[name]William[/name] [name]Dashiell[/name] This is a great choice, I love both names but I would put [name]Dashiell[/name] in first place.
[name]Love[/name] [name]Amelia[/name] [name]Darcy[/name] and [name]William[/name] [name]Dashiell[/name]!
margaret dahlia is BEAUTIFUL 
love thomas dexter & william dashiel also!
I second [name]Susan[/name] [name]Amelia[/name] [name]Darcy[/name] is sweet and [name]William[/name] [name]Dashiell[/name] is handsome!
[name]LOVE[/name] [name]Amelia[/name] [name]Darcy[/name]!
I also think [name]Dean[/name] could be a very cute girls mn.
I like [name]William[/name] [name]Dashiell[/name] as well.
Perhaps:
[name]Silas[/name]
[name]Allen[/name]
[name]Nolan[/name]
[name]Amelia[/name] [name]Darcy[/name] (nn probably [name]Millie[/name])- I really love this! I love [name]Amelia[/name], [name]Millie[/name] is adorable, and I think [name]Darcy[/name] in the middle is excellent.
[name]Olivia[/name] [name]Darcy[/name]- [name]Olivia[/name] is pretty, but very popular. Personally, I prefer your other options and I’m not loving the flow.
[name]Dahlia[/name] [name]Jane[/name]- This is gorgeous too! Very frilly/girly and cute! I love [name]Dahlia[/name] so much. One question: how do you pronounce it? [name]Day[/name]-lee-uh or Dah-lee-uh? I prefer the latter, but that is just my opinion. Also adore [name]Jane[/name] in the middle.
[name]Margaret[/name] [name]Dahlia[/name] (nn probably [name]Maggie[/name])- I like this, too. The flow seems a little off, though, and [name]Maggie[/name] makes me think of baggy. Still, that is just what I think. If you love it, you should keep it, obviously, but I prefer some of your other options.
[name]Charles[/name] [name]Dexter[/name] (nn [name]Charlie[/name])- I really like [name]Charlie[/name]. I also love [name]Dexter[/name]. I like [name]Jill[/name]'s suggestion of [name]Dexter[/name] [name]Charles[/name], too.
[name]Thomas[/name] [name]Dexter[/name]- Not really a [name]Thomas[/name] fan, but again, love [name]Dexter[/name].
[name]William[/name] [name]Dashiell[/name]- This is amazing! I love it! Also love [name]Dashiell[/name] [name]William[/name].
Overall, I would say my favorites are [name]Amelia[/name] [name]Darcy[/name] or [name]Dahlia[/name] [name]Jane[/name] and [name]William[/name] [name]Dashiell[/name]/[name]Dashiell[/name] [name]William[/name].
Good luck! You have great taste!
I also think [name]Dean[/name] would make a great middle name for a girl.