ALEX will be seeing a lot of Katie since she lives with Alicia. I think she would also get along well with Rose and Nat.
HOPE obviously has Josie who is older here because of PGH and she is close in age to Lucy, Morgan and Ezra.
KARA will see a lot of Jacen because she is living with his little brother Anakin :) I also think she and Katie would get along really well.
LISSA has her BFF Rose and I think she would get along well with Jacen and Katie, too. I can also see her and Ezra being friendly. He is more like Rose in personality but they are close in age. Lucy is my other one I see getting along well with Liss! Rose is going to have pre-game Revolt memories (so basically from her early arrival days there before they started waking people up in bigger quantities) so she is 25 and hasn't seen Lissa for a few years. There will be hugging!
SAM is the same age as Morgan, so they will probably have school together. I can also see her maybe sparring some with Rose and maybe they could have a fun mentor-like friendship.
VERONICA doesn't have any immediate connections with my kids, but I do have Charlie's Uncle Gideon who I am sure will visit and I am happy to throw any of mine at her!
These are quick thoughts but I am always happy to throw people together!