Astoria would be friendly, and I think they'd likely know each other well. I think they'd probably get along well, Astoria would certainly understand the shyness and curiosity - though I think Astoria is probably somewhat more confident and sure of herself than Prim.
You did an awesome job on the icons!
ps: i was reading Prim's app and I noticed that you've left the name Heather (instead of Primrose) in the 2nd paragraph of her personality.