Céline Marie Claudette Dion is a Canadian singer, she has started as a musician since 1980.
She has powerful and technically skilled vocals, her recordings have been mainly English and French.
Her debut single “Ce n’était qu’un rêve” in French was released in 1981, peaked #8 on the Canadian QC chart, but didn’t hit in US & UK.
That’s why the song is French I guess.
Her first term, she mainy released in French.
By the way, “My Heart Will Go On” was released as an American film “Titanic Love’s Theme” in 1997, topped in many countries’ single charts, such as in US, UK, Canada, Australia, New Zeeland, Germany, France, and others, in addition to honor “Platinum Disc” in many countries.