I think the beauty in Bella's character is her genuine flaws , does it justify the way she behaved at first , no , but as we progress through the story it's quite clear that she has much deeper layers to her as a character , it's very obvious that her childhood and the way that people labelled her including her own mother who would always assume the worst from her clearly had detrimental effects on her both emotionally and mentally and ofc there is the missing father and the incident with the other girl in the photo ( unexplored as of this point in the story ofc ) , so when those things are taken into account we could understand why she has developed this outer facade and behaves the way she does but inside i think she wants to change and even showed genuine regret when she berated that woman in the bathroom while the MC jacked into her phone , that scene showed that she doesn't enjoy the person she has become
As for the jealousy , think of it as an alpha female marking her territory but yeah that aspect of her personality will pose a problem in the future as the story progresses , despite the hurdles she is the main reason i play and enjoy this game also i just can't ever ignore a chick that's into cars and racing lol