Oops. Just seeing William born 1810 on the 1851 census. He's in Kingswinford with a wife Eliza and a daughter Rebecca age 2 so we indeed have 2 different Rebeccas.
HO107/2036 80 18
Kingswinford, Wordsley, Staffordshire
Jack/Tuck Lane William Penn, head, 41, Drainer of Land, b. Shropshire Kinlett
Eliza, wife, 32, b. Staffs Kingswinford
Ann, dau, 6, scholar, b. do.
Rebecca, dau, 2, scholar, b. do.
William, son, 1, b. do.
MaryAnn Beddard, dau (=stepdaughter, probably), 13, b. do.
Tanja