Rudolph the Red-Nosed Reindeer
In the popular Christmas classic Rudolph the Red-Nosed Reindeer, Rudolph's mother is Mrs. Claus. However, this is a fictional character and her specific name is not mentioned in the original song or television special.
The Real Rudolph
The name "Rudolph" is often associated with the character from the holiday story, but it is also a common human name. Several individuals throughout history have borne this name. Without further context, it is impossible to know which specific Rudolph you are asking about.
Rudolph as a Family Name
The name "Rudolph" could also be a family name. In this case, it is impossible to know who gave birth to a specific "Rudolph" without additional details about the individual.