For yours:
Ally - I really like
Allegra. I would also suggest
Alexandra /
Alessandra /
Alejandra.
Penny -
Penelope is my favorite. Maybe Penarwan (character in Triads of the Island of Britain)?
Charlie -
Charlotte is my favorite. I don't really have any other suggestions for this one.
Jessie -
Jessica,
Jessa and
Jessamine are my favorites. I have a cousin named Jessina "
Jessie".
I don't have a rule of thumb on word names. From your example, I prefer
Brooke,
Rain and
Sky.
Aquinnah - 5 - I have issues trying to pronounce it.
Estella - 9 - I love it, but slightly prefer
Estelle.
Emmeline - 10 - Perfect!
Shea - 7 - It's nice enough.
Cleo - 7 - Same as above. Also, I know a lady who keeps calling my sister (whose name is
Chloe)
Cleo.
Sky(e) - 7 - I like it better than
Skyler /
Skylar, as these are super trendy here.
Brook(e) - 3 - I'm not a fan, negative association.
Rain(e) - 7 - It gives me the impression of calm for some reason.
Keeley /
Keely - 3 - Negative association.
Phoebe - 8 - I think it's sweet and sophisticated at the same time.
Esther - 7 - I like it, but some days I feel like it's too old lady.
Mine
For Girls:
Hattie
Considered:
Harriet.
Lettie
Love:
Eglantine, but I've been told that makes no sense.
Really Like:
VioletConsidered:
Ayelet,
Letitia,
Scarlet.
Lottie
Love:
Charlotte, but I love
Karl more and don't want to use both in a sibset.
Nora
Love:
Elinor, but it's my brother's favorite name, so I'm trying to let it go.
Considered:
Lenore.
Tess
Love:
Artemisia, but I've been told that makes no sense.
Considered:
Theresa.
For Boys:Cam
Love:
Cambyses.
Considered:
Camden,
Cameron.
Denny
Love:
Tennyson, but it's a stretch and I don't really like using surnames as forenames if I can help it.
Considered:
Dennis,
Denzil.
Jamie
Love:
Benjamin, but I love "
Ben" more.
Considered:
James,
Jamison.
Kit
Considered:
Christopher.
Sully
Considered:
Sullivan.