Parmelia Sherwood appears on the 1900 census in Greenwich, CT:
"United States Census, 1900," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:M9QF-QK7 : accessed 11 June 2018), Parmelia Sherwood in household of John H Sherwood, Greenwich township (excl. Greenwich borough), Fairfield, Connecticut, United States; citing enumeration district (ED) 71, sheet 16B, family 299, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,240,133.
Permela Britt appears on the 1850 census in Greenwich, CT.
"United States Census, 1850," database with images, FamilySearch(https://familysearch.org/ark:/61903/1:1:M6D9-QVX : 12 April 2016), Permela Britt in household of James B Britt, Greenwich, Fairfield, Connecticut, United States; citing family 303, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
It looks like it is possible that her sister Maria married one Alexander Ganung:
https://www.findagrave.com/memorial/160327412/maria-l-ganung