SNGF (but on Sunday) - Ahnentafel Roulette

So the rules are that I'm supposed to take my father's age, divide it by four, and then find the person listed as that number on my ahnentafel report and write at least three facts that I know about him/her.  For me, this leads to a woman who I need to research further, my 2nd great grandmother Katie Lamb.

I do know a little bit about her.  Her name appears in a few sources as Kate, Katie, and Catherine C., but I have not yet found her maiden name.  Most of what I know of her is listed in U.S. census records.  She was born in Ireland in either 1848 or, as my notes show more likely, March 1850.  Her parents were both born in Ireland, but I don't yet know their names.  She emigrated to the U.S. in 1853, and married Francis W. Lamb in 1869.

Extract of the 1870 U.S. census.

She first appears as Katie Lamb on the 1870 U.S. census in the 6th election district, 15th ward, New York City, as the wife of Francis, the head of household.  The household also included Rudolph Gebser (b. 1840), James Murphy (b.1844), Mary I. Murphy (b. 1841), Ellen Murphy (b. 1846), Elizabeth Murphy (b. 1850), Maggie Thornton (b. 1854), George Hurlburt (b. 1852), George Estevez (b. 1832) and R. Estevez (b. 1835).  With so many surnames in the household, I'm guessing that Francis and Katie lived in an apartment or something similar and the census enumerator didn't separate the apartments on the form.  I know of only one child to Francis and Katie, Eugene Joseph Lamb, born in New York on 27 October 1872.

Extract of the 1880 U.S. census.

Katie again appears on the census in 1880, still living in New York City.  Again, the head of household is Francis W. Lamb, but this time the household appears to also include only family members and a servant: Ann Lamb (b. 1815), Chas. Lamb (b. 1845), Eugene Lamb (b. 1872) and Mary McSweeney (b. 1865).  I find it interesting that Mary McSweeney is listed as a servant here; the census record says that she was born in New York and her parents were both born in Ireland.  I wonder if the McSweeneys new Katie's family or the Lambs before they moved to the U.S.

Extract of the 1900 U.S. census.

The Lambs were still living in Manhattan when the 1900 census enumerator visited.  What I have so far is at the end of a page image that was emailed to me a while ago; I need to go back to this census to see if there is more of the family continued on the next page.  But, with the information that is here, I am able to determine that this is the correct family.

Extract of the 1910 U.S. census.

Francis and Katie appear on the 1910 census, now living in Brooklyn, but this time with a positive connection to another surname. Elizabeth Murphy (b. 1860) is shown as a sister-in-law to Francis. She is listed as single, and I have yet to determine if she was a widow or more likely (since there isn't an entry in the column for her age at first marriage) an unmarried sister of the spouse of one of Francis's siblings.  I wonder if this Elizabeth Murphy is related to any of the Murphys that appeared on the 1870 census.  Their son Euegene had by this time moved out and started his own family; I have a very low contrast copy of another page from this census showing him with his wife Mary C., three children and a servant.

I don't yet know Katie's death date.  Francis died on 27 January 1917.