Oh my gosh Erato and RJ137 - the information that you are finding around Pauline and her family is just incredible.
I have the US Public Records Index, 1950-1993,Volume 1 that has Pauline E McFarland, born 7 April 1909 living in Seattle, Washington.
Then from the US Social Security Death Index, 1935-2014 I have:
Name: Pauline E. McFarland
SSN: 484-07-3545
Last Residence:
98125 Seattle, King, Washington, USA
BORN: 7 Apr 1909
Died: 10 Sep 1997
State (Year) SSN issued: Iowa (Before 1951)
I am in Australia so my resources for searching are a bit limited, but I am thinking this is still the woman we are searching for as her birth dates certainly match up.