Hi Jean,
I entered the surname " DERWENT " with no luck, I tried " DARWENT " no lucK,
Then I tried wildcards no luck, so I tried the IGI, and found,
16/sept/1825, Phoebe Darwin, Acton Burnell, R.C. bap.
Father Gulielmi Darwin
Mother Annae
I then had a look for Jane Darwin, no luck, not even a Darwin hit, unfortunatly
I do not have the R.C records on my disc, which is a pain because I suspect my ggg grandad was baptised in this church one year later, were your ancestors R.C ? , Gulielmi , is a name I havent seen before, but you have to realise that R.C, records are all keept in Latin, and I havent a clue what this translates to English, perhaps some more experianced reader could tell you,
Hope this is of help to you, let us know if you have any luck Penetrating the R.C. armour,
Best Regards,
Pete.