So I have my first irrelevant certificate. It was a bit of a long shot, but there we go.
My ancestor, Mary Ballance married into the Pickup family, but died before the 1851 census. I found a Mary Ann Pickup in the correct area that died in 1847 so I decided to order the certificate just in case.
Unfortunately this Pickup is a cousin-in-law (? - I get lost amongst the branches!), but she died aged just two weeks. I notice her name isn't on any ancestry family trees so she is a new addition to the history of that family.
One day I will find more about Mary Ballance, but if anyone thinks they are related to Mary Ann Pickup, daughter of John and Elizabeth from Burton Salmon in Yorkshire let me know and I'll send you the information.