Tuthill of Ballyshannon

i am researching my great grandmother fanny or frances tuthill born 1857 in ballyshannon ireland for a few years now but can not find any record of her prior to her marrying my great grandfather james cameron mchattie in sydney australia in 1884
her father was hugh tuthill and her sister was anna marie tuthill who married a david matchett at enniskillen ireland in 1866 who after his death married a charles smith a police officer in sydney in 1876