I am descendent of John and Mary's fourth child Johanna Black (1846-1938).
I will email you (at email@example.com) some Family Group Sheets for Mary Casey.This might give you an outline my information on the couple and sources.
On Mary Casey - I was almost convinced she came out as a first female immigrant on the Red Rover (Arriv. Syd. 13/8/1832) but recently looked the name up in "Fair Game: Australia's First Immigrant Woman" by Elizabeth Rushen and Perry McIntyre 2010 and they have a different person who married a John Reynolds (per Challenger 1832) on 24/9/1833. If this is correct, it leaves her arrival ship a bit of a puzzle.