The following step might clarify whether George Dando and Elizabeth Bridges Dando are your Mary Ann Dando's parents.
The index to the Civil Registration index of births, marriages and deaths can be searched at:http://freebmd.rootsweb.com/
There is an index record for the marriage of John Perry and Mary Ann Dando: Clutton 5c 881 in the March 1868 quarter. (Please double check this at the above website before using this reference!)
If you obtain a copy of the marriage certificate from the records office using the above index reference , it might have the first name and surname of the fathers of the bride and groom. If Mary Ann's father's name is not George, that would clarify things. If it is George, there seem to be a lot of George Dandos, so this would still leave some uncertainty.