Long post but I thought it may be worth compiling a timeline of findings.
17 Feb 1834 - Peter Duncan & Eleanor Sanders marry at Newport, Shropshire
19 Aug 1838 - William Duncuff, son of Peter & Ellen, bap at Stoke Hammond, Buckingham
5 Jan 1840 - Charlotte Duncan bap at Loughton, Buckingham
1841 Census - as Duncan, Peter (25), Ellen (20) & two children at Horsley Fields, Wolverhampton
13 Jan 1844 - Rosanna Duncombe dau of Peter & Ellen, bap at Wolverhampton
1851 Census - as Duncome, Peter (33, coal miner), Ellen (32) and children residing at Staffordshire.
16 Aug 1859 - William Duncomb (20, miner) of Steelhouse Lane married Sarah Preston (18) of Steelhouse Lane at St John, Wolverhampton. Wit: George Lea & Bridget Preston.
Late 1860 - Edward Duncan son of William & Sarah born
1861 census - Sarah (19) & Edward Duncan (6mth) at Eagle Street, Wolverhampton w/ Sarah’s mother Margaret Preston.
1861 census - Peter, Ellen & Charlotte Duncan at Portobello, Willenhall.
William missing from census.
21 May 1861 - Edward Duncan, 9mths, son of William (miner) Steelhouse Lane buried at Merridale Cemetery, Wolverhampton. Grave 435b.
30 Oct 1863 - at No 16 Seymour, Staveley, Samuel Duncome son of William Duncome (miner) & Louisa Garside is born.
1864 - Samuel Duncan baptised at Staveley
1864 - Charlotte Duncan m. Thomas Price
July 1870 - Peter Duncan/Duncome, 65, collier, dies from manslaughter by John Jones. Buried 23 July at Staveley.
1871 Census - Ellen Duncan, William Duncan and Samuel Duncan living with Charlotte Price at Rawmarsh Lane, Kimberworth, Rotherham