Moral dilemma

I am a staff member at a university.  I don't teach.  I do, however, get to know some of the students quite well, and many of the junior staff whom I supervise are graduate students in other programs, working their way through school.  The other day, one of my former staffers mentioned to me in an offhand way that last year, she wrote a paper for another student, and it received an A, so she was determined to take the same class because she knew she would make a good grade.

I was horrified.  I have never cheated on an academic project, test, or paper in my life.  I would never do that.  If I couldn't get a good grade on my own, I didn't want it.  And I certainly wasn't going to do all the work and let someone else take the credit for it.  Probably she wrote the paper for money, and I know her family is poor and struggles financially, and she attends an expensive private school.  I actually asked her to stop talking and not say anything else about it, because I didn't want to know.  I liked and respected this person and had a very high opinion of her integrity until now.  I have no idea what to do with this information.

It strikes me that I have very little room to judge her.  I cheated on my husband.  That's a much more sacred trust than academic integrity.  Actual human beings were personally hurt.  Yes, my ex broke his vows to me, too (that whole love and honor thing), but I am responsible for my own choices, and I took the dishonorable path.  I have remorse (holy crap, do I have remorse), and I am trying to make it right from here on out, but I was dishonest.  I can't undo that.  It's really just a twist of fate that hardly anyone knows what I did.  I could rent a billboard and confess, or something, but I hardly see how that would help anyone.

There are people who would not be friends with me, if they knew what I had done.  There are people who would believe I should have been put to public shame.  I have no desire to ruin this student's life (which I would do, if I dimed her out for an honor code violation), but it really bugs me that she mentioned the whole thing so flippantly, and without any remorse.  And I am having a hard time looking her in the eye now.

Have I abdicated the moral high ground?  I'm really at a loss here.