There are 6 trees on Ancestry that list Samuel Woolsey born 1822 married to Letitia Birch in 1838 in Dublin. They have him dying in Armagh in December 1893. Another 9 trees have Thomas Woodhouse born 1806 marrying Letitia Birch in Dublin in 1838 and then dying in Fiji in 1875. So a warning bell is ringing in my mind as to whether there were really 2 Letitia Birch marriages in Dublin in 1838, and perhaps whether different families may have been mixed up. Also if Samuel was born in 1822 then he’s not very likely to have married in 1838. It would have been legal but very unusual for a 16 year old to be able to support a wife. Not impossible that’s correct but unlikely, in my opinion.
The Gordon Cameron Cunningham tree on Ancestry has Letitia Birch dying in Belfast on 3.9.1884. The couple are shown as having a son Edward 1841 – 1870 who married Sarah Jane McMaster 4.7.1861 in Killylea, Armagh and who died in Sydney in 1892.
One tree describes Samuel as alias Thomas Woolsey alias Woodhouse. One has him born in Co. Offaly in 1807 another in Belfast in 1808. Another has him born in Derrynoose, Armagh in 1821. Some have 1823 (making him 15 when he married).
I searched the Irish death registers for a Letitia Woolsey death 1880 – 1890 but did not find one, anywhere in Ireland.
Here’s the death certificate for a Samuel Woolsey in Armagh workhouse on 9th Nov 1893. (Not December 1893). He was a widower, an army pensioner, and his normal address looks to be Killycor.
Here’s a link to Edward Woolsey's marriage in 1884. His father was a tailor (rather than an army pensioner). Edward was living in Killylea when he married, but that doesn’t mean he was born there.
Apart from church records there are very little sources to research in Armagh for the early 1800s. If the family had land then they would normally be in the tithe applotment records. Those for 1834 list 2 John Woolseys (senior & jnr) in Seagoe Upper. No Woodhouses listed. That doesn’t mean they weren’t living there, just that they had no land so were probably labourers/weavers or servants.
Griffiths Valuation for 1864 lists just 1 Woodhouse. He was James and lived on Bridge St, Portadown. 1 Woolsey who was John and had a house, foundry and associated premises in Foundry St, Portadown. So neither surname was common in the area by the 1860s.
Hard to know what to advise. Some of the information on the various Ancestry trees is questionable to say the least and should not be relied on without verification.
The problem with the likes of a marriage in Ireland in 1838 is that it’s rare for the parents names to be shown. Of course their names might be obtained elsewhere eg from a death certificate or a second marriage but otherwise it can be hard to be sure you have the right family. Some relationships on some trees may be guesswork.
Hopefully you will be able to link up with others who know more about these families.