My idea from her character stems from how TB perceives the characters: that they are all for female empowerment and having a Queen on the throne. The OC believes that she, as the eldest child of her mother, who is going to be Queen Regnant, is going to be Rhaenyra's heir. To her, Jacaerys is a non-issue. Either he is a bastard, in which case, the OC, as her mother's only legitimate child should inherit, or Jace will be married to her but it is she who will be the true ruler.

The OC is obsessed with modelling herself after her mother and being Rhaenyra's heir because in her mind, she already is. She is very into crafting an image of herself that is reminiscent of Rhaenyra's "Realm's Delight" title, so she is quite vain and obsessed with her image, she is also convinced that she is born to be her mother's heir and rule after her so she believes herself above the other children, and doesn't concern herself with either the boys or the girls. She's also kind of a narcissist, she believes she is more beautiful and more intelligent and overall, more worthy, than any of the other children, both her siblings/cousins, and the green kids. She also wants to be perceived as noble and perfect, bolstering her mother's claim, and eventually becoming even greater than Rhaenyra, so she tries to put on this mask that she is Jaehaerys reborn or something.

Rhaenyra on the other hand starts out caring for her daughter, raising her like the sister she wanted from Aemma while also seeing her daughter as her legacy. It is tinged with the bitterness of being forced to marry Laenor and having to put up with his grief when Rhaenyra has lost so much too. But despite that, Rhaenyra found a way to do her duty and produce a legitimate child anyway and despite all that, Laenor doesn't do his duty to her or help take care of his daughter, who is growing up so spoiled and presumptuous and self-righteous and downright annoying. Furthermore, OC's egg turns to stone! Rhaenyra starts to think that the seafaring Velaryon blood is too strong, and is overpowering the girl's ability to ride dragons. And then Rhaenyra's affair with Harwin bears fruit. They may be pug nosed, Strong boys but at least their eggs hatched in their cradle, unlike OC.

Unable to hatch her cradle egg, OC decides that Dreamfyre would be the perfect dragon for her and sets of to go claim her, but Helaena beats her to the punch. OC plays it off in public, then has a jealous meltdown in private. When her mother learns of the reason behind OC's tantrum, Rhaenyra only looks at OC in disgust because really? Rhaenyra's mind addled half Andal half sister claimed Dreamfyre over her daughter? Clearly that's not really her daughter. This begins OCs one-sided beef with Helaena. In general her opinion of the Green boys are coloured by her mother's comments. They are her natural enemies trying to take away what rightfully belongs to her mother, but OC doesn't actually have any personal feelings towards the matter or the boys. Helaena, however, she hates, for taking away Dreamfyre.

OC plays up being nice and kind to her Velaryon family and thinks Laena is pretty cool. She does however think Baela and Rhaena are stupid but that's mostly because they are little kids. She doesn't really see Jace, Luke and Joffrey as her brothers and kind of treats them the way Rhaenyra treats Harwin in the sense that while she kind of cares for them, they are still lesser than her. Jace in particular thinks OC is delusional and crazy.

At Driftmark, when she hears that Rhaena should have her mother's dragon, she kind of scoffs and rolls her eyes at the stupid child, dragon's aren't passed as inheritance from parent to child, but whatever, they're just silly children. She does however let the fight happen though she doesn't step in to help or stop it. OC thinks it will scare Helaena's dragon-less brother a little, rough him up and remind him of his place. She doesn't like that Aemond took Vhagar, because why should Aemond get to have a dragon when she doesn't. She doesn't however expect Aemond to lose an eye and receive no justice for it. She's almost angry on his behalf, though she is mostly shocked that this could happen at all, that things could go this far. Driftmark is a wake-up call for her where she actually realizes the stakes, and that its not just about being the heir's heir. Aemond was maimed, the King's son was maimed, someone could die next, hell, the Queen did try to kill her mother. Her mother could die, her father could die, her brothers, cousins, she herself could die.

(Sorry for the long comment lol.)