In looking at Jane's life, I noted an intriguing difference between The Oxford Dictionary of Saints and Butler's Lives of the Saints. Both record that Jane was a widowed noblewoman, three of whose five children had not survived infancy. The deaths were a threat to her spirituality and vigor.
Here's the intriguing part of the story that David Hugh Farmer leaves out of the Oxford, but Paul Burns chose to include in his edition of Butler. The unnamed priest who began Jane's recovery was a high control martinet who demanded a vow of secrecy from her and then assigned an abusive level of penances and devotions. It's great grist for a gothic novel -- a non-physical, psychosexual relationship with a rich, guilty widow (whose guilt is compounded by her neglect for her living children while she struggles to live up to the priest's demands) and a cruel, charismatic priest who controls a harem of young widows through their sexual frustration and religious terror.
Speaking of confession, I have no idea how far this priest went in abusing Jane, but it seems like the core of a really warped story. I figure Anne Rice would handle it brilliantly. If you know her, please call her attention to it.
Fortunately for Jane, she happened to hear St. Francis de Sales preaching. Well, he wasn't Saint Francis at the time, but he would be after Jane testified at his nomination for canonization. They met individually, in public and chaperoned, and eventually he persuaded her to break her vows of secrecy and obedience to Father de Sade and make a confession to him. He persuaded her that she could have a satisfying, personally fulfilling life as a nun, but the Orders she approached (Poor Clares, Carmelites) would not accept her because of her responsibilities to her children. Being an influential guy, Francis was able to set her up with her own Order, the Daughters of the Visitation of St. Mary (Visitandines). They were originally going to do charitable work, but they realized that, being widows of wealthy men, they weren't very good at taking care of others. They decided to be a contemplative order of nuns instead, and their Order spread quickly throughout France (sixty-five houses in thirty years).
You may think that a contemplative Order is just a house of leisure for rich women, but they sheltered and counselled all women who came to them, which was an important service with guys like Father Koresh running around, getting his jollies by assigning crushing penances. They also offered relief during the Plague of 1628.