Looks like you have the correct census entry - address is same as marriage certificate. What is the significance of 37 written by the registrar to the right of the cert?
From Exeter St. Paul baptisms:
23 Jun 1825 Louisa dau of John & Sally, father a servant of Paul Street
9 Nov 1828 James don of John & Sally, father a labourer of Paul Street
John ALLEN married Sarah SANDERS 4 Oct 1810 Exeter St David
By 1851, Louisa has married Thomas ENDICOTT and she is shown living alone in All Hallows on the Walls, Exeter, aged 25, Married born Exeter, occupation: Furrier.
Also in 1851, and 1861, Sarah ALLEN born Teignmouth 1785 is shown lodging with an Ann TUCKETT. Two Sarah SANDERS were baptised at West Teignmouth in 1785 - check IGI.