To be able to try to help, more detail would be needed. (Only names of people still living cannot be posted.)
From your mother’s birth certificate, can you please give….
Exact date of birth
Place of birth, and include the street address on the certificate.
Name of father
Name of mother
Include occupations of parents if recorded
Who registered the birth? And when.
From your mother’s marriage certificate, what is the name and occupation of her father as recorded exactly.
Who were the witnesses, and do you know how they are related to your mother?