Imogen (Immy) - I also don't really get the appeal of the name. It always sounds like some sort of element to me, like hydrogen.... I just don't fing it pretty at all.
Lucy - Very pretty and classic.
Abigail (Abbey) - I adore Abigail! Prefer the spelling Abby or Abi for the nickname, though, Abbey seems like it adds too many letters....
Penny - Very cute, but I too adore it as a nickname for Penelope.
Michael (Mikey) - Michael's great, classic and always useable. Don't love Mikey, though. I'd prefer just Mike. I've heard Mick too, though, and I kind of love that....
Zachary (Zack) - I'd spell it Zach instead of Zack. Great name though, very handsome.
Charles (Charlie) - I find it to be so old-fashioned. It's not uncommon, I just can't see it on a kid....
Samuel (Sammy) - Love Sammy, or Sam! Samuel's a great name, it's so handsome.
Imogen (Immy)--I'm another person who doesn't really get the appeal of this name; it's kind of odd-sounding to me.
Lucy--LOVE it! My favorite from your list.
Abigail (Abbey)--I like it quite a bit.
Penny--Kind of neutral on this name.
Michael (Mikey)--Seems kind of overdone.
Zachary (Zack)--I like it a lot.
Charles (Charlie)--Love! My favorite from your boys' list.
Samuel (Sammy)--I like it a lot.
Lucy & Charlie are my favorite but may not work as a sibset bc of charlie Brown haha
I love Lucy and Abigail
Penny is cute but it doesn't sound complete to me...like the pp said, I like Penelope nn Penny
Imogen is such an odd name to me...I know a lot of people who like it but I don't see the appeal
All your boy's names are fine imo but I don't personally love or dislike any of them
Imogen--Immy is cute, but I just don't like the sound of Imogen. I think of it as more of a "fantasy story" name. I think Immy could work as a nickname for something like Camilla or Emilia.
Lucy--A cute, old-fashioned name.
Abigail--Abigail is a nice name but very common right now. Also, I would spell Abbey without the e, since Abbey looks like a word to me.
Penny--Cute. Personally, I prefer is as a nn for Penelope.
All the boy names are great.