I didn't find any of them after the 1880 Census. I think it's reasonable that the parents and sister Angie died before the 1900 Census. Don't know what happened to the children although the majority were girls and probably married.
I'd check the records in FamilySearch, Records, Collection for Bradford County. They won't be indexed.
You can also contact the Bradford County Historical Society, www.bradfordhistory.com/index.asp?pageid=18
and ask if they have a local death index, indexed newspaper death notices and cemetery inventories.
Also the Bradford County Library, www.bradfordcountylibrary.org/local-history/
has genealogical records. Successful Searching!