Hi Julia
I am pretty sure this is your mysterious Ann E
Anne E CADWALLENDER - shows as married John LEIGHTON 1875 in Durham
Marriage DEC QTR 1875 Durham 10a 560
CADWALLENDER Ann Elizabeth
LEIGHTON John
This marriage also shows on the Durham records index as definitely the two that married each other
http://www.durham.gov.uk/gro/newgro.nsf/search?open&C0425009140614062005$
I have also found her with her family in 1871, in Wombridge Shropshire
RG10/2810 Folio 26 page 45
RD Wellington
SubRD Wombridge
ED 4
Civil Parish Wombridge
Ecclesiastical parish
Oakengates
Town Oakengates Thomas Cadwallader b 1821 Wombridge, Shropshire Head Coal Miner
Margaret Cadwallader b 1825 Wombridge, Shropshire Wife
Enoch Cadwallader b 1847 Wombridge, Shropshire Son
John Cadwallader b1848 Wombridge, Shropshire Son
Isabella Cadwallader b 1852 Wombridge, Shropshire Dau
Ann Elizabeth Cadwallader b1857 Wombridge, Shropshire Dau Eliza Cadwallader b 1860 Wombridge, Shropshire Dau
Rosannah Cadwallader b1862 Wombridge, Shropshire Dau
Thomas Cadwallader b 1864 Wombridge, Shropshire Son
William Cadwallader b 1866 Wombridge, Shropshire Son
The street address is Ketley Bank
There are a number of CADWALLENDER/CADWALLADER family members in the Durham area by 1881 giving place of birth as Ketley/Kelly Bank so it looks like they all moved up there. Also she names one of her children Enoch.....
Hope this helps