You can see by the 1880 census that Lena's middle initial was "E" also that John was called on the census "Holden J."
On the 1900 census in wd5 Olean, Cattaraugus Co, NY: Adams, Andrew b. Jan 1834, age 66, widowed, b. Canada, became a citizen in 1890, has resided in the US for 30 yrs. dau Ethel b. March 1877, age 23, b. NY, both parents b. Canada, occ. Schoolteacher
I think this is possibly them, but I don't see them in later censuses.