IKR!!
Does he think is fun to hide a huge part of herself from almost everybody most of your life? And getting upset over her quitting...What did you think would happen? that she would continue to crossdress the rest of her life and not look for a way out? She is a commoner woman from a single mother that has lived her entire life as a man, she has too much on her plate already! don't just assume things will get fine and dandy the moment you confess and say you knew the greatest secret of her life for years!
Only Albert's family (minus his mother), Mary and the crown Prince know (her aunt has suspicions) everyone else doesn't know. There is a point to stay hidden, but I do agree that Albert could at least be like "I know you're a female. I always knew. Especially my father but I won't ridicule you because of it and won't judge. As I haven't done so all these years. You can live as you want, even be a maid if you wish and I'd still protect you as you're important to me" since really there is no difference, all he has to do is just state he knows.
ARGH I'm so upset!! She try very hard to pretend to be a boy, but everyone know this and the ML even make fun of her! Why don't he say the truth? This will be soooo good for her and even for him! It kill the good mood for me, because I'm so sad for her, she can't quit her job and she can't be a girl for now... If it was me I think I would die for stress and sadness! Argh it's hard to explain, but this situation is the worst for me, she hide something but everyone know, so what's the point of hidden this? She can't be cute or girly, and it must have been so hard to live hiding her sex (and period!! 0.0) since her childhood! I hope I'm not the only one thinking that, and hope when she discover that he known, she's going to be very ubset and not forgiving him at once!
(sorry for my English, I'm French ^^')