Data source is the pamphlet, "Genealogy of One Branch of the Jacob Mumma Family", written by Ellen Landis Mumma in 1970
http://ia700303.us.archive.org/33/items/brubachergenealo1884brub/brubachergenealo1884brub.pdf
It is unclear why Fanny moved to Derry Township. in the 1840 & 1850 census
*****************************
1840 Census, PA, Dauphin Co., Derry Twp., p. 200
Widow Muma, 1 male under 5, 1 male 5-9, 1 female under 5, 1 female 5-9, 1 female 15-20 (probable error in Widow Muma's age - should have been 20-30).
1850 Census, PA, Daupihin Co, Derry Twp., p. 133, 29 Aug 1850
Fanny Mumma, 41, b. PA
Elizabeth " , 19, b. PA
Fanny " , 13, b. PA