@ James: Like Phil said I can´t find any references to Jeanne de Lestonnac as "protector". However, I found some references to "Saint" and "Blessed".

@ Mercedes:
You can take it from here, but I leave you with these references for further research.

Les Châteaux de Landiras et de Montferrand and Their ...
www.scirp.org/journal/PaperDownload.aspx?paperID=37207
by DA Bailey - ‎2013 - ‎Related articles
Keywords: Montferrand de Guyenne; Landiras; Saint Jeanne de Lestonnac; Bordeaux; Hundred Years' ... The city of Bordeaux was to capitulate on 23 June. Dunois ... to guard both Dax and Blaye, which were too far apart to defend simulta-.

Renaissance and Reformation; Saint Jeanne
(“Joan”) de Lestonnac (1556-1640)
While discussing the Wars of Religion, we alluded to Gaston
II de Montferrand-Landiras. He may have trained as a lawyer
and become a member of the Parlement of Bordeaux, and so a
colleague of his future father-in-law, Richard Lestonnac.22 He
may otherwise have performed little of note himself during his
less than twenty-year possession of the lands and titles adhering
to this cadet branch of the house of Montferrand. But in 1573,
he married ***Jeanne de Lestonnac, who was to become the fam-
ily’s most renowned member—the only saint born and bred in
Bordeaux.*** Although only seventeen years old at the time of her
marriage, Jeanne’s life had already been filled with the drama
of late 16th-century France.

CATHOLIC ENCYCLOPEDIA: Bordeaux - New Advent
www.newadvent.org › Catholic Encyclopedia › B
The Faubourg Saint-Seurin outside the city was a great centre of popular ... of Saint-André, which he placed under the protection of the municipality; and it was ... order of the Filles de Notre-Dame, founded by Blessed Jeanne de Lestonnac, ...

Among the Archbishops of Bordeaux, in the modern epoch, may be mentioned: Charles de Gramont (1530-44), who during its earliest years helped the College of Guyenne (founded in 1533) and introduced into Bordeaux the art of the Renaissance; François de Sourdis (1599-1628), who had great political influence during the minority of Louis XIII, caused the marshes in the neighbourhood of Bordeaux to be filled in, erected there a magnificent Carthusian monastery, welcomed to Bordeaux many congregations devoted to ecclesiastical reform, approved (1606) the teaching order of the Filles de Notre-Dame, founded by ***Blessed Jeanne de Lestonnac***, and befriended the College of the Madeleine founded by the Jesuits in opposition to the College of Guyenne which, during the sixteenth century, was open to Protestant influences, Cardinal de Cheverus (1826-36), who during the cholera epidemic had the sign Maison de Secours (House of Refuge) put over his palace, of whom M. Jullian said that no prelate in the history of the diocese had come nearer the ideal of sanctity, and during whose episcopate Thérèse de Lamourus, the "Good Mother", considered by Cardinal Cheverus a saint worthy of the early days of the Church, opened for repentant women the Maison de la Miséricorde; Cardinal Donnet (1837-82), who re-established the old provincial councils interrupted for 224 years.