So let me get this right....
Tuckney married Mary Ann Carr after the death of Rebecca who died pre 1861.
His son Joseph married his step sister Mary Ann in 1868 who died in childbirth in 1877. He then marries Mary's sister and his step-sister, Ellen Carr in 1879.
Blimey - he was supposed to be a travelling reverend for the Baptist church so my dad was led to believe.
Of course then he married my great grandmother Ann Eliza Harrison in 1899, so I guess Ellen must have died sometime before then.