John may have been married before he married Mary Mather and each had one daughter (Ann and Elizabeth). The three birth registrations for Elizabeth Haslam are for other families, so Elizabeth wasnt born a Haslam. Therefore Ann may be John's true daughter. There are 8 possible birth registrations for Ann Haslam (1841-1843), but only one has a matching marriage for John Haslam (a minor). However, that is to Hannah Cubbin, married 29-Oct-1838 so John was too young. Also, their family in Turton extended 1839-1860. Therefore Ann is Also Mary's.
In 1851 John Haslam (27) and wife Mary (33) were at 6 Dale Street, Bolton Emmanuel with Elizabeth (5), James (1) and sister Hannah (24).
In 1861, John and Mary (35 & 40) were at 12 Emmanuel Street with Elizabeth (16), Ann (20), James (12), John (10), Ellen (8) and Sarah (6)
In 1871, John and Mary (49 & 52) were at 20 Emmanuel Street with James (21), John (19), Ellen (17), Sarah (15), Thomas (7) and married daughter Ann Neaham (28)
In 1881, John (58, Wid) and unmarried daughter Sarah (25) were living at 65 Nobel Street, West Bolton.
In 1891 and 1901, John (64, the 78) was living with his married daughter Ellen Whitman (or Wittam).