Gender: Feminine
Origin: Latin
Meaning: “lucky.”
Eng (faw-STEE-nah)
The name is a feminine form of the ancient Roman cognomen, Faustinus, which in itself is derived from Faustus, meaning, “lucky.”
The name was a common one among the Nerva-Antonine dynasty, being borne by several women in that family, most notably, Anna Galeria Faustina the Elder (100-140) and her daughter of the same name (125-175).
Other forms of the name include:
Fausta (Italian)
Faustina (Croatian/German/Italian/Lithuanian/Spanish)
Faustyna (Czech/Polish)
Faustine (French)
Fausztina (Hungarian)
Male versions include:
Faust (German)
Faustino (Italian/Portuguese/Spanish)
Fausto (Italian/Portuguese/Spanish)
Faustus (Latin)
Faustinus (Latin)
The male version of, Faust is the subject of a German folklore, in which a man by the name of Dr. Faust makes a deal with the devil. This story was later adapted into literature by Christopher Marlowe and Goethe, and was even adapted into a famous opera.
Other notable personages include: Roman noblewoman, Rupilia Faustina (87-138); Faustina, wife of Constantius II (340-366); Faustina Constantia, daughter of Faustina and Constantius II; St. Faustina of Como, a 6th-century Italian saint;Â Italian Mezzo-Soprano, Faustina Bordoni (1697-1781); Saint Faustina Kowalska, a 20th-century Polish nun and saint (1905-1938).
The designated name-days are: February 15 (Poland); September 23 (France) and October 5 (Poland).
Source
Legitimate Baby Names 
My husband has a Faustina on his family tree. I laughed when I came across it because it just sounds so ridiculous to my modern ears. But Faustina’s parents were definitely adventurous baby namers. Their other daughters are Monta and Gwendolyn.
Faustine is not unusual in France.
Is your husband’s family French by any chance?
Nope, not French. Definitely unconventional, though. The girls’ father was named William Byron, but he chose to go by Byron or By.
I am searching for info on my name Frostine. Faustine is the closest I can come so far.