I believe it is fairly clear with a look at the available records that Marie Jeanne Materne (AKA Thily / Thili), daughter of Johann Adam Materne, sister of Marguerite Materne was the wife of Jean Madere. I would call your attention to the records (particularly No. 249) I list at the end of this note excerpted from the book:

Natchotoches 1729-1803: Abstracts of the Catholic Church Registers of the French and Spanish Post of St. Jean Baptiste des Natchitoches in Louisiana by Elizabeth S. Mills (New Orleans: Polyanthos, 1977)

At the time of the baptism of Jean Maderne on August 7, 1744, Marguerite Materne was the wife of Thomas Leger. This indicates that there existed a sister to sister link between the two. This, in addition to the repeated uses of Materne, Maderne and other variants make it clear to me that they are of one family.

I don't have a copy of the book - but I seem to recall reading further references to this situation as well as more on "Jean des Jeans" in the book:

Abstracts of the civil records of St. John the Baptiste Parish 1753-1803 by Conrad.

I will go to the library and re-read it on the weekend.
As to the parentage of Jean Madere I have some possibilities to pose:

1. The 1731 Census of Farms' Concessions shows a MADRE family only a stones throw from Jean Adam Materne's 8 Arpents of land where Marie Jeanne grew up - I have not looked at this family at all but it would seem a likely candidate. I would love to hear from anyone who has looked at this family.

2. A trail I'm chasing: the possibility the widow of Johann Adam's brother and her female child being present in St. Johns parish in the late 1720's causing some confusion in later years.

3. Of course, consanguinity cannot be ruled out at this point - not a pleasant possibility but a possibility none the less.

I look forward to more exchanges on this issue - I enjoy factual, documented discussion.

Excerpts:- - sorted here chronologically.. (X)=individual made his/her mark (S)=signature

Page 29, No. 229:
Reine Jeanne Maderne, February 7, 1743, baptism of Reine Jeanne, born February 6, 1743, daughter of Jean Maderne(X) and Marie Thili, habitants. Godparents: Pierre Fosse ( X ) and Jeanne Malathi (S), habitants.

Page 47, No. 362:
Reine Jeanne [Mader], April 4, 1743, burial in parish cemetery of Reine Jeanne, in presence of father, aged three months.

Page 32, No. 249:
Jean Maderne, August 7, 1744, baptism of Jean, born August 6, legitimate son of Jean Maderne and Marie Thili. Godparents: Pierre Fosse, elder warden of this parish and Marguerite Thily, wife of Thomas Leger, habitants of the parish of St. Pierre des Allemands, in whose abscence Marie de La Croix (X), wife of Francois Chaniot, habitant, has served.

Page 35, No. 277:
Jeanne Mader, January 18, 1747, baptism of Jeanne, legitimate daughter of Jean Mader and Marie Thily. Godparents: Daniel Pain (S), Surgeon and Jeanne Chever

Page 38, No. 308:
Marie Jeanne Madere, September 22, 1749, baptism of Marie Jeanne, legitimate daughter of Jean Madere, habitant, and Marie Thily. Godparents: Pierre Barrio, son of the Govenor of the Adayes, and Jeanne Rougot.

Page 68, No. 552:
Fancois Daniel Mader dit Jean des Jean, January 6, 1753, baptism of Francois Daniel, legitimate son of Jean Mader and Marie Materne*. Godparents: Francois Daniel Pain (S) and Manuel Clemence Borne, represented by her mother (who is Marie Elizabeth Borne). *Above this name, between the lines, is written the surname "Thily"

Page 73, No. 598:
Marie Francoise Mader, June 29, 1755, of Jean Mader and Marie Maderne*. Godparents: Jacques Lambre (X), and Marie Francoise Bourdon ( X ). *The surname "Maderne" has been written over with the name "Thily"

Page 99, No. 798:
Jean Mader dit Jean des Jean, fils, [no month and day] 1756, burial of Jean Mader dit Jeans des Jean fils. [fils is french for "son"-this record is most probably the death of an infant or stillborn unnamed son]

Page 84, No. 694:
Cecile DESJEANS Mader [sic], December 1, 1758, baptism of Cecile, daughter of Jean des Jean* and Marie Maderne*. Godparents: Francois Le Vasseur (X), and Cecile Le Vasseur (X). *The name "desJeans" is written over in text with the name "Mader" and the name Maderne has been written over with the name "Thily." In the marginal reference, the name DEJEANS has been lined through and replaced with "Mader."

Page 101, No. 821:
[Jean Mader dit] Jean des Jeans, April 21, 1758, burial of Jean des Jeans, elder warden of the church.

Page 62, No. 506:
Cecile Mader, February 5, 1761, burial of a small daughter of Sr. Jean des Jean Mader.

Page 62, No. 507:
Jeanne Maternes, March 20, 1761, burial of the widow of Jean Mader, who died after receiving the last rites.

Page 57, No. 457:
Francois Carles / Jeanne Madere, March 25, 1761, After publication of one ban, marriage of Francois Carles (X), son of Jean Carles and Marie Merles, Native of Marceille [Marseille], bishopric and parish of La Quaterne?and?Jeanne Mader (X), duaghter of Jean Madere and Marie Materne, native of this parish. Witnesses: Buard (X), Sieur Lambre, the younger (X), Sieur Lambre, the elder (X), Pain (S) and Sr. Monteche (X).