Update!
I just found them coming out to New South Wales (Australia)
Sarah's mother is ELIZABETH Black, father Robert Black, and when she were on their way they had their son Robert Rutherford with them - he was 13 months old.
It's pretty clear that she was from Desertcreate in Tyrone. James is listed as a native of Cookstown. They arrived on a ship named Elizabeth on 23 Aug 1841.
James parents are listed as John & Margaret.
He was 22 & she was 21.
Cheers
Andy