Steven,
The Valuation revision records on the PRONI website show that after Robert’s death the farm was taken over by John Donaghy in 1887 and then by Patrick Donaghy. This is presumably that farm in the 1901 census:
https://www.census.nationalarchives.ie/pages/1901/Tyrone/Mountjoy_Forest_East/Erganagh_Glebe/1746159/
You will see from the house and building form that the farmhouse had walls of brick or stone, a thatched or wooden roof, 2 windows at the front; it had 3 rooms and was rated as a 3rd class building. If we then go to the 1911 census you will find a little more:
https://www.census.nationalarchives.ie/pages/1911/Tyrone/Mountjoy_Forest_East/Erganagh_Glebe/874698/
The out offices return there tells you there was a stable, a cow house, a calf house, a fowl house and a barn.
Mountjoy Presbyterian church (known as Crossroads till 1878) has records starting in 1821. There’s a copy in PRONI in Belfast. The church was established in 1791 but sadly there are no records 1791 - 1821.
Here’s a marriage for Eliza Hanna in 1859 in Cappagh Church of Ireland. Tradition was to marry in the bride’s church so you might want to consider whether it may have been the family church. My guess is that it was:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1859/09578/5472881.pdf
Cappagh COI records start in 1753. Copy in PRONI.
Margaret 1878 married in the same church:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1878/11117/8069648.pdf
Charles Hanna married 1881 in Omagh 2nd.
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1881/11018/8028656.pdf
Mary Hanna married 1864 in Cappagh COI:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1863/09658/5502445.pdf
James Hanna’s marriage in Mountjoy Presbyterian (but as I have commented, that’s likely to be the bride’s church):
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1879/11066/8048847.pdf
