postman44 - You don't give the source(s) of your information on Mary Banks Payne, and so it is difficult to decide how reliable it is. To eliminate some of the uncertainty I have obtained a copy of her birth certificate. Key information thereon is as follows:
When and where born:
Fourteenth
January 1900
1 Beach Street
Herne Bay
U.D.
Name, if any:
Mary
Banks
Sex:
Girl
Name and surname of father:
[blank]
Name, surname and maiden surname of mother:
Ada Mary
Payne
Housekeeper
Domestic
Signature, description and residence of informant:
A M Payne
Mother
1 Beach Street
Herne Bay
When registered:
Twenty first
February
1900
As you can see, this gives a slightly different date of birth to the one you have previously quoted, but confirms that Ada Mary Payne was her mother. There is nothing to connect Ada with William Herbert Banks, so where did you get his name from?