chempat - Thank you so much again for your help and digging into this!
I'm not sure about the baptism to be honest, I think that perhaps the vicar was just being officious as you say, as they didn't have any family in the area, so it's unlikely that she was related to them. I guess she may have been a Harding at birth, but it does seem a big coincidence to have the same surname!
The 9th October 1882 birthday comes from the 1939 register. I'm not sure who would have provided the birthday on her gravestone - although the WWII Civilian Deaths record mentions her husband Arthur, they had been estranged for some time when she died. I would presume that it would have been one of her children who gave it, or perhaps even her sister-in-law. Martha was living with her husband's brother Egbert and his wife (also called Martha Ann) at 103 Earle Street when their house was hit by a bomb, killing both Martha and Egbert. There's a whole big mystery in the family as to why her and Arthur separated, as after her death he just disappeared and none of the family heard from him again. I've found his recruitment records from 1915 and apparently he gave false information when signing up, and then deserted a few months later, so we think that possibly had something to do with it.
Her father Henry died in 1893, but her mother Martha died a year after the wedding, so she should still have been around. In the 1911 census she does say that she had 0 children from her marriage, but I don't know whether this is because Martha was adopted, or whether they had disowned each other.
PrawnCocktail - Thank you so much! I will look further into this, as I think you might be on to something there!
