I think it just means she felt she was ruining Rin's life seeing her getting in happy and not being able to do anything besides work herself to death.
Seeing that she is more cheerful and that her happiness is not her responsibility anymore ended up being a weight took from her in a good way, seeing Rin is moving on from her past.
Seeing that she is more cheerful and that her happiness is not her responsibility anymore ended up being a weight took from her in a good way, seeing Rin is moving on from her past.