Her marriage certificate will give her father;s name, which would be a help. It's not tricky, I need more clarity with the way you are giving the information it is disjointed and confusing.
You have Grace Ann Wilson born 1903 Richmond (Is that surrey ot North Yorks?) You want to know her mothers maiden name, you have the marriage cert for Grace and Jack Wilson, what is Grace's father's name on the marriage cert and how old is grace when she married and when was that?