She likely died in childbirth.
1850: Census, Bendersville, Adams, Pennsylvania
Richard Fitzgearls 32, b: MD, teacher
Letty Fitzgearls 43, b: MD
Sarah Parker 20, b: PA
From Adams County Historical Society Tombstone readings
Sarah T. (wife of E.W. Mumma, MD)
d. Jan 23, 1859 26y, 7 Mo, 25d
1. David P. MUMMA (b. MAR 1854, Bendersville, Adams Co., PA - d. 19 FEB 1932, Philadelphia, PA)
2. Julia M. MUMMA (b. 6 JAN 1856, Bendersville, Adams Co., PA - d. 6 JUL 1893, Menallen Twp., Adams Co., PA)
3. Ella Eugenia MUMMA (b. 6 FEB 1858, Bendersville, Adams Co., PA - d. 10 JAN 1948)
4. Edward Woodyer MUMMA (b. 1 AUG 1858, Bendersville, Adams Co., PA - d. 13 SEP 1877, Bendersville, Adams Co., PA)