is mavis gallant a prominent writer

Yes

Mavis Gallant is regarded as one of the finest short-story writers of the second half of the twentieth century, as well as being an essayist and social commentator.

She is an extraordinary writer and a leading literary figure in Canada since her first short story, published in 1951, She has grown to be considered internationally as a modern master of the genre. Her writing is nuanced, sensitive, gifted, deep and concise.