The information I have is as follows:
Michael Prendergast (1878-1903) married MaryAnne Flynn (Farranfore, Co. Kerry). Mary and Jack Brosnan had one daughter, Mary, who married Jack Brosnan as far as I know. They had 5 children, 3 daughters, Joan, Kathleen and Mary, and two sons, Mick and Tom. Tom married Peg Pigott.
Do these people sound like the right family to you?