There are a few trees on Ancestry and checking the facts I do not believe Isaac's daughter Sarah was born in Headley, Hampshire!
Isaac's daughter Sarah was married to a John Lemon/Lemmon with children born in Ontario. At least 2 of the trees I looked at showing Sarah was born 1828 Headley show her as being in both the English and Canadian census at the same time! As far as I can see, the Sarah Lemon born in Headley, Hampshire never left the UK! In 1861, for instance, is with husband John (an agricultural labourer) in Bramshott, Hampshire with one, possibly 2 children, and also in Perth, Ontario with husband John who's an Innkeeper and with 4 children!!
Also, Headley baptisms are online and there is no Sarah Rowe baptised there.
So, it would seem that a John Lemmon/Lemon married a Sarah Rowe in Ontario and another John Lemon married a Sarah bc.1828 Headley, Hampshire in the UK and the latter couple never leave the UK. These are 2 different couples I'm afraid so all that is known (from her death certificate) is Sarah Lemon, nee Rowe was born in England. After seeing the death certificate simply stating born in England I kept wondering how it was known she was actually born in Headley, Hampshire. With no baptism for Sarah Rowe there I looked at a couple of the trees again and then spotted that they had John/Sarah Lemon living in 2 places at the same time - somewhere along the way someone has confused UK and Canadian census records and attributed them to the same couple i.e. the ones in Canada whereas they are definitely 2 different couples (who coincidentally appear to be the same sort of ages).
Can I ask, please, how you know that Isaac Rowe was a) married twice and b) that first wife was named Sarah Uln?
Annette