I have been searching for a birth/christening date for my great grandmother Isabella Galloway. According to information I have (Ancestry) she was born in the Sep Quarter 1858 in Alverstoke, Hampshire. Her parents were south of the border working

But I can't find her on Family Search or the LDS BVRI CD's.
Is there a reason the record isn't showing on either, or will it be a case of eventually having for pay for the record at the registry office? Not a cheap option either, or simple.