The Mystery of Mme. Rieux

So, I know we're finished with The Plague at this point, but I've been meaning to post this for and just finally got around to it.

The character I find most fascinating in The Plague is Rieux's mother. We don't get a lot of information on her, and, interestingly enough, the information we do get on her seems to be almost all from Tarrou's point of view, not Rieux's. However, even with just that little bit of information she is presented to us as one of the heroes of the story, a quiet hero. She is not actively involved in fighting the plague like the men all are, but she is serene, and Tarrou sees in her an angel or a saint, someone the plague is not capable of touching. I've tried to find articles on her, but so far have had not luck with that, and she continues to enthrall me. I want to know what she means!