Hi! The reason she has the larger room with enough space to fit her desk is that I work when she's out at school/work during the day from 9-5 so have the common space/whole apartment to myself when I work, so I get that privacy, and she needs her privacy after 5 or on weekends when she needs to study and I'm home so her office isn't in the common space. I did however expect to still be able to use the nice sunny front balcony anytime though since we agreed to share it and since we split the rent down the middle, but I'm now realising that it's an invasion of privacy.
Think of a big big lofty room with a living room/tv in the middle, a desk in the corner of the back of the room and a kitchen which has an open wall attached to that big common space. Our bedrooms are both closed off. We figured that splitting rent down the middle made sense since my desk takes up room in the common space, and that I personally don't like the idea of working where I sleep so it seems to even out a little regarding office space without taking the balcony into consideration.