@sweet-potato @Stoner Everyone is different. For people used to corsets or are okay with tight clothing, corsets might be no big deal.
I'm assuming the feel of the corset is different from her usual chest binding.
So even though she does bind her chest, she might feel uncomfortable wearing something
unfamiliar. That coupled with new attire and a new environment might make her more uncomfortable since everything is a sign she is in a place out of her "league".
Though my guess is that she is the illegitimate child of Noble as well. So I'm assuming soon we'll find out it's very much her league.