Pruning the family tree

 I received this message in FamilySearch Messages:

I'm afraid you have the wrong Ann Waller as your ancestor - Henry and Martha's child born 1812 in Rogate died at birth so can't have gone on to marry anyone! Her death record is now attached.

Anxiously, I looked at the attached death record, The name, date, place and parents are an identical match for the christening record. Ouch!!! That Rogate christening record perfectly matched Ann's birth year and place in the censuses. Unfortunately, the christening record made no reference to the death of the child that same day. So I spent hundreds of hours researching the wrong family line. 

Date Child Father Mother Surname
02/08/1812 Ann Henry Martha WALLER

Alas the message from the other researcher is right! The death date, place and parents are identical to the birth info in the Rogate Baptismal Register. 

I had to prune 5 generations of research from my family tree. And although I know where and when Ann married James Forsbury, it does not appear in the civil registration index so I cannot order the marriage certificate which should list her father’s name. The church marriage record does not list the fathers of the bride and groom, so a primary source may not exist. 

At present the best prospect is a christening in 1814, where the parents are James Walder, a carpenter from Habin, a mile south of Rogate, and Elizabeth or Bet. 

18/12/1814 Ann James Elizabeth (Bet) WALDER Carpenter from Habin. 

Maybe Ann was born in 1812 and not christened until 1814? Or maybe she was christened in some other parish? I have searched but found no other good prospects.