What language did the Virgin Mary use when speaking at Lourdes to 14-year old Bernadette Soubirous, according to Bernadette's own reports of the apparition?

According to Bernadette's account, during that same visitation she again asked the lady her name but the lady just smiled back. She repeated the question three more times and finally heard the lady say, in Occitan, "I am the Immaculate Conception" (Qué soï era immaculado councepcioũ, a phonetic transcription of Que soi era immaculada concepcion by someone not literate in Occitan).

https://en.wikipedia.org/wiki/Bernadette_Soubirous

And in case you're wondering what Occitan is, read all about it at
https://en.wikipedia.org/wiki/Occitan