Well, there are so many complicated 'tales' in this Twist / Aston history! Starting with the discovery some years ago that my gg.grandfather (the William Twist) changed his name from Twist to Aston for reasons of bigamy I think ! It seems he took his mother's father's name and used him as his father on the marriage certificate to my gg.grandmother. That is why I believed Emma was William's mother.
I have checked a number of birth entries for William Twist around 1839, writing to B.ham Registrar, but none have given Emma as the mother. I had never noticed the age gap on the 1851 census between the children, so something went on there it seems. I did look under John and William Aston, in case they had her name, but nothing seems to be right.
William Aston, Emma's father could have been dead by 1859, as it was not always entered was it.
I give here the details as typed up in my file for the death of Emma :
It was discovered that Emma had two consecutive death certificates issued in 1859. This is unique because the first is usually struck through with 'this is superseded by' or it is deleted. On the second certificate Emma is registered with her father, William Aston, water carrier, as next of kin and given with her maiden name as Emma Aston. The first certificate gives her name as Emma Twist and her next of kin is given as Joseph Twist, horse dealer. After discussions with the Superintendent Registrar it was felt that the most likely explanation is that Emma and Joseph were not married. 'Ann Clark', who's name appears on both certificates as the informant, registered Emma as Joseph's wife and afterwards realised it could be seen as illegal and went back and re-registered her, giving her father as next of kin instead.