John and Betty had all their children baptised at Bolton St Peter. There must be another John and Betty Lever family in Bolton, as there is also a baptism for Martha in 1825, just 6 months after James.
The 1837 BMD birth record (not GRO) for Mary Lever, shows the MMN is MATHER.
In 1841, John and Betty (37 & 38) were a Joiner's Square, Great Bolton with James (16), Sarah (13), Wiliam (9), Charlotte (6) and Mary (3) .
In 1851, John and Betty (47 & 48) were with James (26), Sarah (23), Wiliam (19), Charlotte (16) and Mary (13) in Great Bolton