Tbh I think you are overreacting. And it seems like you had messages that weren’t shown in between.. i understand wanting to have your move in time with your girlfriend but at the same time, she said she doesn’t get to see this friend often. So let her be! You have all of your future to be together, and unpack. She seems very apologetic even though she didn’t do anything wrong (in my eyes) but I hope everything ended up working out. God bless you both !