Katie is part of this organization herself. So does Daphne. As I believe, girls with earrings are part of the organization and have a special mission. And these are the best of the best. So don't underestimate Kelly. She's very smart. Notice that she is sitting on Charlie's right hand. By the way, her behavior with Sasha is very similar to how Katie behaves with Willy.
I am surprised by this, as I haven't seen anything explaining earrings in either game other than where Nami got hers. Leia wears earrings, and seems to be the new kid on the block that the Organisation wants to prevent from building her own empire. If you think Leia gave up her earrings because she refused to finish her mission, but then goes to the bookclub to hang out (she was there a year ago, 7 years after she gave away her earrings).
Leia (or someone) passed one to Nami, before Summer disappeared, when Nami was 10 or 11 (Nami recieved the earring when Nika and Summer went somewhere else without her, but before the cabin incident, 'easily eight years ago' according to the script - how can Nami know her mission when she's 10 or 11? This is the ONLY time earrings are directly mentioned in either game rather than shown.
About the organisation, I can believe Kelly might be and Charlie is creepy enough.
Also, as list of girls with earrings:
Bella (multiple different kinds, not always), Nami, Victoria (sometimes), Sasha, Nia (doesn't wear them all the time), Zara (sometimes), Nadia, Vanessa, Ayua (doesn't wear them all the time), Amber, Claire, Summer, Nora and Miriam. And that's just looking through the CG gallery. Some wear earrings in some renders and take them off elsewhere.
So far, Mila and Stefanie are the only confirmed LI definitely without earings, and we don't know about Sonja or Elsa. For the other's even Sasha doesn't wear her earring all the time - she's not wearing it in the bar scene
. I find it hard to believe that 70% or over of the confirmed LI's are on missions for the organisation. Why would Ayua stop Sasha from questioning Nami about her earring, if they're all on missions?
If I go to WiaB, Miru (not all the time), Leia, Katie, Daphne, Zoey, Monica, Katarina, wear earrings. Helen, Gina, Scarlet, Abigail and Dana don't wear earrings, or have long hair hiding any. So over 50% ov the main female charatcers are on missions? This means over 50% of William's Family and over 50% of his friends in Wollust are on missions if the earring this is true.
Jessy/Donna, who is almost guaranteed to be working for the organisation and is likely on a mission following WIlliam around (if old plots carry any weight) doesn't wear earrings.
So i'm not convinced yet there's any significance in earrings other than ocean likes women wearing them. We'll see, you might be right.
Edit, I mean no significance *other* than Sasha and Nami's being identical to Leia's old earrings. That is a given suspicion, it's pointed out in too many renders.