I read this entry as:
1841 Wales Census
Bryn Tirion, Rhanhir, Llangerniew (Llangernyw), Llanrwst
David Parry, 21, Ag. Lab, Denbighshire
Jane Parry, 21, -, Denbighshire
Catharine Parry, 2, -, Denbighshire
John Parry, 12m, -, Denbighshire
Note that John is 12 months old not 12 years. It also looks like one family to me.
This may not be the Jane you are looking for?