It might help to know that there is an extracted christening record on the IGI for Mary Orme 28 NOV 1798 St Nicholas, Liverpool, parents William Orme and Mary Bradburn.
There is also one for Sarah Orme 18 DEC 1797 Saint Peter, Liverpool parents William Orme and Mary, so this one is not conclusive and before the date of the marriage you have found so could be a different couple.