Sue, I think street is Eldon Lane. The BMD Registration District for this area was Auckland. The FreeBMD site shows death registrations at Auckland RD for a Hannah Johnson( in June Quarter of 1851- just after 1851 census was taken on 30th March)... and several for a Mary Johnson ( including one for same June Qtr 1851. On the death indexes are on line- just showing bare details- only way to be sure is to buy the certificate with full details. I can see the family in Shildon on 1861 census ( page ref 4928-40-7). Do you have them on later censuses or did they leave England ? Michael