Norah O'Donnell understood the cultural differences that led Iranian President Mahmoud Ahmadinejad not to shake her hand before their recent "CBS This Morning" interview, and to request that she not cross her legs. But his references to her as "the lady" were almost too much.

"I had to repeatedly bite my tongue and not say, 'You know, my name is actually Norah O'Donnell,'" she said. "I thought the questions were more important."

Wise decision. It would not have resulted in the kind of publicity a rookie morning-show host needed during her first month on the job. O'Donnell, who jumped to CBS last year after more than a decade at NBC News, replaced Erica Hill within the trio of "CBS This Morning" hosts that also include Charlie Rose and Gayle King.

O'Donnell has the chance to learn her trade and build a following in the relative obscurity of a perpetual underdog program. Competitors Robin Roberts at ABC and Savannah Guthrie at NBC have more viewers but also more pressing problems: Roberts trying to recover from a rare blood disease and Guthrie facing an audience defection following the dismissal of Ann Curry.

O'Donnell, 38, grew up in Washington journalism. As an ABC News intern, she grabbed a notebook and stood in the back of the room at a White House news conference with President Bill Clinton. She worked at Hotline, then as a reporter for Roll Call.

Her job at Roll Call led to frequent cable television appearances and eventually the job at NBC. She was a White House correspondent during President George W. Bush's administration and hosted a daytime show on MSNBC. Leaving NBC was a tough decision but O'Donnell saw more opportunity at CBS, where she would be White House correspondent, chief substitute for Bob Schieffer on "Face the Nation" and eventually, perhaps, Schieffer's replacement.

That was until getting a call this summer from CBS News Chairman Jeff Fager and President David Rhodes, asking to see her.

"I figured I must be in trouble if they both wanted to see me," she recalled. Instead, they offered her the job on "CBS This Morning."

The new gig required some personal juggling. O'Donnell and her husband have 5-year-old twins and a 4-year-old daughter. She flies to New York Sunday nights and leaves after the show Thursdays to have three days with her family. Friday she works from a Washington studio.

Still, O'Donnell said, "It's not the kind of a job you turn down." Her family is expected to move north this winter.

"Morning TV is the crown jewel of broadcast journalism," she said. "Where else can you do two hours of live television with the audience that we have?"

That audience isn't nearly as big as it is for "Good Morning America" and "Today." Sometimes, it's about half the size. But there have been positive signs lately; viewership was up 3 percent over last year and ratings up 13 percent among the key audience of women age 25 to 54 during the week that ended on Sept. 21. CBS hopes to take advantage of a tumultuous time at its rivals.

The CBS show differs from its rivals in that two or all the hosts may conduct newsmaker interviews together. In an unspoken way Rose and O'Donnell often settle into different roles, with Rose looking at the big picture and O'Donnell boring in on specific points to try and advance news stories. She tried twice to get Ann Romney to comment on Clint Eastwood's Republican convention speech on the morning after; the answer was more evident in Romney's face than her words.

O'Donnell confronted Ahmadinejad with an underling's declaration that Iran was supplying aid to Syrian President Bashar Assad's military crackdown on his own people. The Iranian leader chuckled, denied the statement and made it clear that he saw the interview more as sport than a way to provide information.

Licht said he's seen O'Donnell come in and change the direction of segments based on some reporting calls she had made the night before.

"She has sources," he said. "She goes on the air with information not that she's gotten from a one-sheet but from picking up the phone and calling sources."

O'Donnell did have something of a blank look on her face one day last week as she sat at the anchor desk with Rose, King and musician Dwight Yoakam. She winced recalling an admittedly star-struck chat with Serena Williams. Morning TV requires a command over a broad range of subject matter, and that's something O'Donnell needs to work on.

"I am so used to concentrating on facts and what politicians have said in the past and what votes they've made, that it is sort of a different experience for me to step back and have a conversation with people who are successful in sports or music or innovation in business," she said.