I'm posting a site: See the 5th Item "children with one citizen parent and one non-citizen parent"
(At least 5 of the 10 years that your parent lived in the United States must have been after your citizen parent's 14th birthday.
http://www.illinoislegalaid.org/index.cfm?fuseaction=home.dsp_content&contentID=976
It's irrelevant. She could have been 13 and it wouldn't impact Obama's citizenship status. The passage you're referring to deals specifically with foreign birth, not birth on US soil.
The citizenship status of your parents has absolutely no impact of your citizenship if you're born on US soil and your parents aren't armed foreign invaders or foreign diplomats. See: United States v. Wong Kim Ark, 169 U.S. 649 (1898).
Ping for later
Yes, if he was born on foreign soil, she could not have passed on US citizenship to him, if married to the father.