There is Confusion by Jessie Redmon Fauset

Maggie and Philip had returned from the sanitarium to New York, but Philip undoubtedly was dying. Peter and Harry Portor were at his bedside every day, but not because of their ability to help him. They were simply three friends together. Philip never spoke to Peter of the incident at Des Moines, though it is probable that he thought of it many times, but the young doctor seemed so serenely unaware of any former misunderstanding that Philip, with a deep sense of relief, let the whole incident slide out of his mind.

Joanna, meanwhile, was experiencing a little private purgatory of remorse and grief. As she saw Philip's joy in Maggie, his complete and unbounded satisfaction in her presence, she became more and more overwhelmed with the awfulness of that old unconsidered act of hers, the sending of the letter which had caused Maggie to marry Henderson Neal. Maggie had never told her this, but she was pretty sure that such was the case. The mere fact that Maggie had never spoken about it to Peter, even in the days of their engagement, led her to suspect that her sister-in-law had attached more significance to it than she had cared to show. There was only one thing for her, if she was ever to know any peace, and that was to confess to Philip.