Yes, but Roxas and Namine were born at the same time, from the same action, involving the same 2 people. Moreover, according to AtW's reports, both of them were derived from Sora's body and soul. It's similar to how a single zygote splits to produce identical twins. Though in reality, identical twins are always the same sex because, again, they originate from the same zygote. I don't know what in the ever-loving fuck was left of Kairi to give to Namine, but whatever it was made Sora's make body appear female.
Sure hope replica bodies don't have real DNA, or are infertile at the very least.
Except Naminè was born out of Kairi and her Heart. Kairi herself had nothing to provide or give to Roxas, so therefore your biological theory has no ground whatsoever. And neither is it canon. Roxas wasn't created of Sora and Kairi at all, neither were any zygotes split, so they
can't be twins. Roxas is accumulation of Sora's discarded body, birthed from his heart, with Ventus' influence deciding how he would look like. Nothing was derived from Kairi.
Naminè is basically Kairi's shadow, a ghost if you will, of herself. Sora being present merely gave her the chance to physically exist in the plane they are in, but she did not gain or was given any part of Sora. She has nothing to return to him, she has nothing that belongs to him, and thus, 100% fully returned to Kairi...because she's Kairi, putting aside the metaphysical aspect of agency. It's why she's never been referred to as anything more than Kairi's Nobody, officially and in-game. And why she and Sora were able to coexist. Touching Kairi had Naminè start to blur and dissipate in KHII when they were running away together for example.
So you can say,
metaphorically, that they were created at the same time because of the one incident, but they are not
at all biologically related and are two separate existences with separate components. What you stated would cause inconsistencies to the canon and will need explanations as to why Naminè was not at all necessary to wake Sora up or had her Heart divided between the two if you really think she was both of them. As was Roxas. Don't know what your attempt was for this.
Perception is what matters here to me rather than that anyway. From what I've gathered in 358/2 Days, I did not view Roxas and Xion as romantic. Their actions towards each other are no different than what the other gang of friends do. Xion says she loves both Axel and Roxas on her private journal, without at all thinking those feelings as conflicting. Then once she herself said she's Roxas and Sora, either she must have a twisted point of view of wanting someone romantically/sexually, or that defines how she sees her other self. And this matters because that's how she determines what their bond is. Doesn't help that nothing occurred in KHIII...and if anything would have, it should have been there to be established, considering how hard they pushed SoKai.
Even Terra and Aqua had a more touching, personal moment during the Eraqus and Xehanort scene, although I haven't made up my mind about them objectively speaking. They can go either way.
I like the concept and potential of Roxas/Naminè because they fulfill what the other lacks. Roxas is full of confidence, individuality, self-worth, and fought against what everyone thought he should do until he had nothing left to make him stay. Naminè is the opposite. While she's made great progress since CoM thanks to Sora's kindness, the isolation and verbal abuse she endured for basically her entire life had her become a pushover. She gained a spine, but unlike Roxas, she fully accepted her fate and that she was a creature that was never supposed to exist.
Nonetheless, she provides that intuitive, calm behavior and demeanor that has Roxas actually shut the fuck up and listen...because
she listened to
him as a person first, as an equal, instead of one to be coddled. He saw that and depended on her in the tutorial. She achieved what his friends failed to provide and that was the truth. It didn't matter what the consequences were. He had the
right to understand things about himself and make his decision. It's crazy that he got that from someone who he didn't spend much time with yet left an impact nonetheless.
There needs to be more to conclude what it is they are to do with their specific relationship, yet that's something that'll be answered in the future once they get to physically interact again instead of Roxas being spurred emotionally by having him gaze at her mansion from within Sora in KHIII
.
She should have reunited with him or Kairi or both. Kairi particularly would have provided a level of depth for the two females that has nothing to do with penises ala Elsa and Anna. Disney has actual competent writers on staff though.
Hell, when I think about it, Kairi and Naminè even visually take after them.
EDIT: If you want me to play your inaccurate game, however, my "poison" will be RokuNami (if done right down the line). But it's not a poison. So.
It's hard to ship anything in KH honestly. Sora and Kairi are the only ones canonly, romantically viable and set up to be that way, but I'm just...not interested or invested :/. Roxas and Naminè are in limbo, and Terra and Aqua needs a bit more to convince me on what side they're aiming to be.
Gula and Ava are mighty fascinating to me.
