Malcolm,
I understand your reluctance to see McGinnis and McGreece as the same name. However they are pronounced much the same here and if you weren’t especially literate, the spelling and pronunciation fits fine.
The conundrum you face, if you don’t think it’s the same name family, is if Ellen was the deceased Patrick’s sister (as per his death certificate), and Rose Ann Teague, was her daughter and his niece (as per 1880 birth certificate and the 1901 census), how do you think they are related if not brother & sister? Can you suggest an alternative explanation? I can’t. (Plus from her marriage certificate, Ellen’s father was named Hugh which fits with the information you gave).
I note your doubt about the ages. In general, people in Ireland in the 1800s didn’t celebrate birthdays, didn’t have birth certificates or passports (though they might sometimes have had a baptismal cert) and often had little accurate idea of their ages. Most ages on official documents were just a guess.
Alexander Irvine was born in 1863 in Antrim town and became a Minister living in the US. This extract from his book “The Chimney Corner revisited” perhaps explains why people often had to guess their ages:
“My mother kept a mental record of the twelve births. None of us ever knew, or cared to know, when we were born. When I heard of anybody in the more fortunate class celebrating a birthday I considered it a foolish imitation of the Queen’s birthday, which rankled in our little minds with 25th December or 12th July. In manhood there were times when I had to prove I was born somewhere, somewhen, and then it was that I discovered that I also had a birthday. The clerk of the parish informed me.”
I have attached a letter which I found in parish records in PRONI (the public record office) in Belfast from someone in Pettigoe, Co. Donegal in 1908 writing to his Minister, asking for proof of age (ie a baptismal certificate). All he knew was that he was between “70 and 78 years of age.” He clearly had only the vaguest idea of his age and couldn’t narrow it down to within 9 years. (The reason for the letter was that the old age pension was being introduced in 1909 for people aged 70 and over. Documentary proof of age was required. Thus, probably for the first time in his life, establishing his age accurately became relevant to him).