cup of wine's manga / #Strong female lead(22)

Am i the only one or is that red hair girl really annoying?? Cant keep her mouth shut, cant respect bro sis code, cant understand that in fact she is the newcomer in that trio to the point cant stand that that guy (her bf) care so much for hee won eventhough she bloody understands heewon's circumstance. I know she is supportive towards heewon, but being deffencive and bitchy over that childhood friend caring for heewon-- just how insecure are you?? If i were heewon, i'll drop that bitch out. People like that will only make heewon and that guy's relation further away, and it's a red flag.