It might be this woman. She seems to have at least one sibling named Felicite - don't know if that helps or not? The location is correct but would require more research.
(Also noted on some data that Ben is listed as Ben Pierre Fairfax - must be a nightmare to cover all those spellings!)
From familysearch.org
Good Luck
Louisiana, Births and Christeningshttps://familysearch.org/pal:/MM9.1.1/FWGX-G6J
Maria Zephalia Bertrand Female
birth 27 Jun 1847 GRAND COTEAU, ST LANDRY, LA
father: Jean Baptiste Bertrand
mother Marie Doralise ...
indexing project (batch) number: C52379-1
Felicite Bertrand Female
birth 02 May 1852 GRAND COTEAU, ST LANDRY, LA
father Jean Baptiste Bertrand
mother: Marie Doralise ...
indexing project (batch) number: C52379-1
US Census, 1850 St. Landry parish, St. Landry, LA
Charles Bertrand M 33 LA
Domitele Bertrand F 25 LA
Celine Bertrand F 8 LA
Marie Bertrand F 4 LA
Ju Pre Bertrand M 20 LA (? don’t know if that’s a misspelling/abbrev for Jn Bpt or if it’s a junior – or if it’s even the correct man).
U S Census, 1900, ED 68 Police Jury Ward 8 Mallett & Plaquemine Point, Justice of Peace Wards 18-19, St. Landry, LA
head Benjamin Fairfax M 54 LA marr abt 1875
wife Maria Fairfax F 55 LA 15 children 11 living
dau Elizabeth Fairfax F 23 LA
dau Josephine Fairfax F 20 LA
dau Victoria Fairfax F 17 LA
dau Bernadette Fairfax F 16 LA
dau Aleda Fairfax F 13 LA
son Francis Fairfax M 11 LA
son Henry Fairfax M 9 LA
son Noah Fairfax M 7 LA
son Sidney Fairfax M 6 LA
