Whatever Happened to Eliza Kirby?

Eliza Dorman was born in Co. Wexford, Ireland sometime in the early 1840’s.
She married John Kirby in Dublin 1863. Later that year they went to America where they stayed for
2 - 3 years before returning back to Dublin.
John Kirby died in 1869 Leaving Eliza with 3 children; Jeremiah Joseph, Julia Catherine &
John Michael.
In 1881 the family were living in London at various locations. Eliza (Elizabeth) was living with her sister Anne Bray in West Ham. Occupation given as Nurse
In 1891 the only Eliza Kirby born in Ireland in the whole of London was living in Willesden as a Cook along with Julia Kirby (Servant) also born Ireland.
In 1896 she was shown as Godparent to one of her grandchildren born in Fulham. This is the last sighting of Eliza Kirby. I have a page of a letter written in the early 1900’s written by her daughter-in-law to her grand-daughter giving dates of birthdays of members of the close family which indicates to me that ‘Grannie Kirby’ was still alive at that point.
I cannot find her anywhere on the 1901 census here on in Ireland nor any death records. She wasn’t living with any of her children or other relatives.