Not sure if this is the right Anna, but the following census record appears in West Hempfield Twp in the 1880 census, page 37B. An Anna Mumma, age 76, widow also appears on this page. Age is correct.
Father:Abraham MUMMA (b. 17 JUN 1836, PA - d. 7 JUN 1924, Lancaster Co., PA) Mother:Elizabeth "Lizzie" THATCHER (b. 4 FEB 1845, PA - d. 25 OCT 1936, Salunga, Lancaster Co., PA)
Siblings:
1. Margretta MUMMA (b. 6 JAN 1862, Lancaster Co., PA)
2. Infant MUMMA (b. 5 MAR 1864, Lancaster Co., PA - d. INFANT, Lancaster Co., PA)
3. Clayton Andrew MUMMA (b. 26 AUG 1865, Rapho Twp., Lancaster Co., PA - d. 18 DEC 1941, York, York Co., PA)
4. John Wesley MUMMA (b. 25 AUG 1868, Newtown, Rapho Twp., Lancaster Co., PA - d. 5 MAR 1950, York, York Co., PA)
5. Infant MUMMA (b. 5 OCT 1873, Lancaster Co., PA - d. INFANT, Lancaster Co., PA)
6. Abram MUMMA (b. 18 JAN 1880, Lancaster Co., PA - d. 1896, Lancaster Co., PA)
7. Elizabeth S. MUMMA (b. OCT 1881, Lancaster Co., PA)
8. Albert Hector MUMMA (b. 19 SEP 1885, Newtown, Rapho Twp., Lancaster Co., PA - d. 20 JUN 1958, Mt. Joy, Lancaster Co., PA)