A former lawyer, the 55-year-old Karua has said if she doesn't win the presidency, she will retire from politics.
She equates her leadership to that of a mother, and has said she will run the government like a household and not let her children go hungry.
Her campaign slogan is "Simama na Mama," which translates to "Support Mom" in Swahili.
The University of Nairobi alumna is a contender for the National Rainbow Coalition-Kenya party.
Four others are running, including former banker Peter Kenneth, Mohammed Dida, Paul Muite and James Ole Kiyiapi.