Ann Dunham's birth name is Stanley Ann Dunham.
According to the image of Obama's birth certificate at FactCheck.org, her maiden name was Dunham. She was named Stanley Ann Dunham at birth (her father had wanted a son); but she did not like her first name, so she used her middle name, Ann.
Her full name at birth was Stanley Ann Dunham, but she preferred to use her middle name (Ann).
Stanley Ann Dunham was the first name of Barack Obama's mother. After her husband died, she married another man by the name of Lolo Soetoro and changed her name to Stanley Ann Dunham Soetoro. When they divorced in 1980, she then changed her name to Ann Dunham Sutoro.
Her birth name was Stanley Ann Dunham; she preferred to be called Ann. When she married her second husband, she was briefly known as "Ann Dunham Soetoro."
Jack Dunham's birth name is Jonathan Dunham.
Monet Dunham's birth name is Monet Cherise Dunham.
Patrick Dunham's birth name is William Patrick Dunham.
Robert Dunham's birth name is Robert Dean Dunham.
Sonny Dunham's birth name is Elmer Lewis Dunham.
Dunham Stewart's birth name is Michael Dunham Stewart VI.
Paige Dunham's birth name is Paige Brown.
Her maiden name was Stanley Ann Dunham. She went by Ann. (Her father's name was Stanley, and supposedly, they wanted a boy, so that is why she got a man's name for her first name.)