I think this is Johanne Jensen's father Jens Jensen in 1834 and 1840 in an earlier marriage. If I have the right records here, Johanne Jensen is the first child (or first surviving child) in the marriage of Jens Jensen and Johanne Larsdatter/Larsen, born 9 years after half-brother Jens. So it could be she is named after this wife Johanne who must have died; that would fit with Danish naming custom.
Holbæk, Merløse, Ugerløse, Uggerløse Bye, En Gaard, 11, FT-1834, C1283
Jens Jensen 32 Gift Gaardmand
Johanne Jensdatter 24 Gift Hans Kone
Karen Marie Jensdatter 2 Ugift Deres Børn
Ane Sophie Jensdatter 1 Ugift Deres Børn
The address given above is a farm at Uggerløse Bye/Village.
Holbæk, Merløse, Ugerløse, Uggerløse, 22, Et Huus, 52, FT-1840, C2555
Jens Jensen 38 Gift Gaardmand !!
Johanne Jensdatter 32 Gift Hans Kone
Ane Sophie Jensen 7 Ugift Deres Børn
Marie Jensen 6 Ugift Deres Børn
Jens Jensen 1 Ugift Deres Børn
+ 4 tjenesfolk
Comment by transcriber of census: "erhverv 'Gaardmand' svarer ikke til "22, Et Huus"
I think this means the occupation of farmer doesn't fit with the address given (22, a house, which seems to be a street address in the town).