I wonder if they (the author) has done some gl series with a happier end/something more lighthearted but it's understandable if it's more grounded in historical reality
As hurtful as it was, what she said was true. Kiyouko (I think that was her name) shouldve known what marriage entailed, she did, but she just didnt want to accept it as her choice of marriage wasnt a choice she made for herself.