Found on the FreeREG website:
County Northamptonshire
Place Higham Ferrers
Church St Mary the Virgin
RegisterNumber
MarriageDate 20 Oct 1789
GroomForename Jonathan
GroomSurname PARKER
GroomAge
GroomParish Higham Ferrers
GroomCondition Widower
GroomOccupation labourer
GroomAbode
BrideForename Susanna
BrideSurname MANING
BrideAge
BrideParish Higham Ferrers
BrideCondition Widow
BrideOccupation
BrideAbode
GroomFatherForename
GroomFatherSurname
GroomFatherOccupation
BrideFatherForename
BrideFatherSurname
BrideFatherOccupation
WitnessOneForename
WitnessOneSurname
WitnessTwoForename
WitnessTwoSurname
Notes by banns
FileNumber 30258
However, there's also this one on the Northamptonshire Marriage Index (1700-1837):
22 DEC 1795 - Jonathan PARKER and Susanna COX (both otp) at Burton Latimer CofE
(The above are the only two Jonathan PARKER/Susanna(h) marriages on the index.)
Unfortunately, FreeREG doesn't have the relevant transcriptions for Raunds baptisms, but it may be worth having a general look-around to see if their children can be found anywhere.
Pennie