>>4472252
She doesnt. Probably a misunderstanding on your part because they talked about her working in the "sex industry", but they were jumping the gun. She just works for the maid/house cleaning service which is not prostitution. During the latter parts of her social link she considers going to the "sister company" (aka prostitution) out of desperation to pay the money, but we dont know if she would have actually gone through with it and Kasumi was there to save her anyway.
I wouldnt hold the desperation against her. She just wants to keep being a teacher and atone. Thankfully her mistress took care of it.