You asked for "evidence to the contrary." I provided evidence to the contrary, via UPI.
Are you now saying the UPI is unreliable ("not clear") when its article states that "Obama described his birth..."?
Do you think would UPI lie or cover up or confuse its readership in regards to reporting an alleged statement by the President of the United States? That is a stretch. That is not reasonable.
If you are asserting that a close Obama family member (O's half-sister) is wrong concerning such a fundamental fact of her half-brother's life, please provide evidence to back up your assertion that she is in fact wrong.