Presumably you are aware of her, and some of her family's, presence in Belfast in the Census records:
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* 1911 *
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http://www.census.nationalarchives.ie/pages/1911/Sligo/Calry/Colgagh/755866/house 2 in Colgagh (Calry, Sligo)
Name: Eliza Ann MEGAHY
Age: 85
Relation to Head: Visitor
Religion: Friend
Born: Co Cavan
Occupation: Farmer
Marital Status: Widow
Years Married: 59
Children Born: 7
Children Living: 7
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http://www.census.nationalarchives.ie/pages/1911/Antrim/Windsor_Ward/University_Road/170231/house 27 in University Road (Windsor Ward, Antrim)
Name: James C MEGAHY
Age: 45
Relation to Head: Head of the Family
Religion: Society of Friends
Born: Co Antrim [CJ: Conflicts with 1901 census record of "Co. Cavan".]
Occupation: Baker & Confectioner
Marital Status: Married
Years Married: 5
Children Born: -
Children Living: -
Name: Annie S MEGAHY
Age: 25
Relation to Head: Wife
Religion: Society of Friends
Born: Co Armagh
Occupation: -
Marital Status: Married
Years Married: 5
Children Born: -
Children Living: -
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* 1901 *
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http://www.census.nationalarchives.ie/pages/1901/Antrim/Windsor_Ward/University_Road/977332/house 10 in University Road (Windsor Ward, Antrim)
Name: James C MEGAHY
Age: 38
Relation to Head: Head of the Family
Religion: Society of Friends
Born: Co Cavan
Occupation: Confectioner
Marital Status: Not Married
Name: Eliza Ann MEGAHY
Age: 75
Relation to Head: Mother
Religion: Society of Friends
Born: Co Cavan
Occupation: Retired
Marital Status: Widow
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http://www.census.nationalarchives.ie/pages/1901/Antrim/Duncairn_Ward/Duncairn_Street/957924/house 19 in Duncairn Street (Duncairn Ward, Antrim)
Name: Kate MEGAHY
Age: 38
Relation to Head of Family: Head of Family
Religion: Quaker
Born: Co Cavan
Occupation: English Confectioner
Marital Status: Not Married
[CJ: Hmm, same age as James C MEGAHY, so maybe they were twins ...]
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More to follow soon on Co. Cavan.
Capt. Jock