Responses
It's because at this point the amount of hate she has the prince is not for karl but for her because that is the only thing she is living for and her end goal. She still doesn't realise that kael doesn't care anymore and that he has her right now besides him and he cares about her, you can tell he put the whole issue past him but still didn't forget about it so he is not close anymore with the prince or diana but he doesn't hate them. ( that what i feel like reading the manhwa without reading the novel since maybe some people have read the novel and have a different opinion)
can you really blame hestia for still being angry?
i feel like the people that really care for you gets more mad when something happens to you, than you do so even if hes moved on, she still remember what happened in her past life and interacting with them eye to eye(esp diana) wouldnt really subdue her feelings just make it worse