Stephanie,
There’s a baptism in Magheraculmaney, Co Fermanagh for John Maguire on 15th November 1846 to Francis & Sarah Maguire. The sponsors were George McCrea & Margaret Maguire. That seems to fit the information you have given.
https://registers.nli.ie/registers/vtls000632829#page/59/mode/1up
Likewise there’s a baptism there on 23.8.1844 for Catherine Maguire to Francis Maguire (no mother's name recorded). Sponsors George & Margaret McCrea. You don’t mention Catherine in the 1850 census so possibly she had died.
I found a marriage for Francis Maguire & Sarah McCrea on 12.4.1839, also in Magheraculmaney. Witnesses John Maguire and George McCrea.
https://registers.nli.ie/registers/vtls000632829#page/85/mode/1up
I didn’t find baptisms for Mary, Ann or James.
Neither the 2 baptisms nor the marriage record provide a townland (address) so I can’t tell you where in the parish the family lived but at least you know the approximate area now. Magheraculmany RC parish includes Magheraculmoney & Drumkeeran civil parishes. That’s an area around the village of Kesh, north of Enniskillen.
You say that Francis isn’t in the 1850 census. One explanation could be that he had died. Death registration didn't start in Ireland till 1864 and few RC parishes kept burial records. None for Magheraculmany anyway. Tracing a possible death may not be possible, unless he has a gravestone. If he was a farmer he might, but if he was a labourer he probably won’t.
As you probably know, Maguire is the most common surname in Co. Fermanagh and so tracing the correct family will be difficult.
I searched Griffiths Valuation for Fermanagh for 1862 for George McCrea buit did not find one. There were 5 McCreas in Drumkeeran civil parish. William in Lowery, John in Springtown, William in Springtown, John in Springtown and John in Drumgowna West.
http://www.askaboutireland.ie/griffith-valuation/index.xml
Most of the McCreas in Fermanagh appear to have been protestant, judging by the 1901 census. However the Springtown family were RC. They were still farming there in 1901:
http://www.census.nationalarchives.ie/pages/1901/Fermanagh/Clonelly/Springtown/1353851/
I do not know if they are your McCrea family but they are the only RC McCrea family in Fermanagh in 1901. (McCrea is essentially a Scottish surname, not Irish and I wonder if originally Sarah's family were Protestant (like all the other McCreas in Fermanagh) in which case they are probably descended from Scots settlers who arrived in the 1600s.
Springtown is a mile or so from Pettigoe.
The tithe applotment records for 1832 list a George McCrea in Drumgawny (civil parish of Drumkeeran) so perhaps that’s your George. Drumgawny is probably Drumgowna West.
http://www.irishgenealogyhub.com/fermanagh/tithe-applotment-books/parish-of-drumkeeran.php
Griffiths Valuation (1862) has a John McCrea farming in Drumgowna West as mentioned before. The family had gone by the time of the 1901 census so I don’t know what denomination they were:
http://www.census.nationalarchives.ie/pages/1901/Fermanagh/Clonelly/Dru…
The valuation revision records on the PRONI wesbite show the Drumgowna West McCrea farm changing hands to Patrick Doonan in 1867. There’s a death that might fit with that for a John McCrea on 24.10.1865, registered in Irvinestown, aged 70.
There’s a Margaret McCrea who died 31.10.1879 in Derrin aged 85. Informant was her son Thomas of same townland. She was a farmer’s widow. Derrin is somewhere close to Drumgowna and I wonder if that’s George’s widow (and Sarah McCrea’s mother).
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1879/06498/4870663.pdf
I can’t locate Derrin precisely. It may be a local name rather than a formal townland but it’s in the Clonnelly registration sub district so it’s close to Drumgowna.
