The 49-year-old talkshow host, who announced in early December that she is engaged, confessed that she knew she would marry Rounds a week after she met her.
"I knew about a week after we met!" O'Donnell told Us Weekly. "But I did the smart thing and didn't propose right away. You know, I'm at the age where I just knew. I knew she was exactly what I wanted."
O'Donnell went on to say that she was so nervous about the proposal that she could not look Rounds in the eye.
"I proposed with my head down, hand out and a huge lump in my throat," she added.
Last week, O'Donnell revealed that she has actually been engaged to Rounds for months, adding that she was reluctant to announce the news publicly.