Hi Liz
I think on the Census returns the information was given by one person in the household and maybe in some instances that person was not fully aware of ages/places of birth and guessed.
In my experience my GtGt Grandmother every Census shaved a few years off her age so she was always down as younger than she really was to an extent that her headstone states her age at 68 when she was really 78!! So her death certificate is also wrong as this information was given by the informant or her medical records, not sure which!
As regards Miss Morrison though this was a bit way out so not sure in this case what to think.
Sandra