Mary "Lewelln" (Scott) Offill aka Mary Louellyn Offill was reportedly born on March 1, 1815.
That would seem to date this photo somewhere around 1880-1890.

Teresa Ellen (Offill) Rosswas born November 25, 1845 and died April 13, 1886.
That would date this photo circa 1885.

Virginia Lee "Jennie" Ross was born February 2, 1867 and died April 12, 1888.
That would date this photo circa 1884-1888.
Virginia was Reuben Fletcher Ross' daughter.

Rebecca L. (James) Ross was born September 14, 1831 and died April 21, 1882/1892 in Neodesha, Kansas
That would date this photo circa 1882 - 1892.
Her appearance in this album raises many questions.
Rebecca was the wife of Reuben Truman Ross. Reuben was the apparent the brother or cousin of John Nelson Ross,
father of Reuben Fletcher Ross. Reuben Truman Ross' parents have never been positively identified.