Hi Lynn,
An idea for your consideration - tracking Martha Cooper. This shows -
The 1881 census for Samuel Wilkinson shows 2 children Harriet A and Mary E with him being a widower. His wife Martha (nee Cooper) died in 1880. The findagrave.com web site shows the death of Martha Cooper Wilkinson at Stapeley on 9 May 1880 (Buried at St Chad, 12 May 1880) - I assume this is her.
Stapeley is just south of Nantwich and the details show her birth as 11 Feb 1847 at Bunbury, Cheshire. She was baptised 17 Mar 1847 the daughter of Samuel and Ann (nee Vickers) Cooper. Samuel being from Wrenbury.
At home with Samuel (age 58) in 1871 (living in Coppenhall) is his wife Ann, and John 18, Samuel 12, Ann 10 and Mary 8. Whilst they are described as children, I wondered if the Mary (who is the only one whose birth place is shown as Coppenhall) could have been Martha's child/his granddaughter born 1867 and possibly mistranscribed or described by them as a daughter for the benefit of the census?
I can see Martha in 1851 at home and think in 1861 as a servant with her sister Alice with the Horton family (her place of birth is shown as Harlington but it appears to be her age 13 with Alice being 19).
Maybe a long shot but does this help to tie thing down to the Nantwich area? Martha's whereabouts in 1871 is still a mystery, but the family details all point to the Wrenbury/Nantwich/Coppenhall corridor and show no signs of going anywhere near Weaverham.
Alan