Four isn't enough for Rosie O'Donnell.  She and her fiancée Michelle Rounds are hoping to add to her brood with another baby.

"She's trying to get pregnant," Rosie told guest Dr. Mehmet Oz on an episode of her talk show Friday.

O'Donnell and Rounds have had a whirlwind romance.  They met at a Starbucks, and became engaged only a few months later, in early December.

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"Michelle is seeing a fertility doctor," a source told Us magazine. "She is really excited and they cannot wait to add to their family. Rosie goes to all of her doctors' appointments with her and is really supportive."

The pair is hoping to wed later this year, with Rosie's four kids in the wedding party, and her brother walking her down the aisle.

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Her talk show episode with Dr. Oz airs Thursday on OWN.

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Tough love or loving support?

Rosie O’Donnell sits down with Dr. Oz on her OWN talk show on Friday and Monday to discuss her struggles with her weight and reveals that she has a secret workout weapon -- her fiancée Michelle Rounds.

“I had all of this stress, and I said it was the worst day, and I yelled at these people and she said ‘OK, you gonna go work out?’” Rosie tells Dr. Oz Michelle doesn’t let her rest on her laurel and is supporting her in her weight loss goals.

“She didn’t say it meanly, but she said, ‘We can talk about it while you’re on the treadmill.’”

Despite being personally invited by the man himself, Rosie O'Donnell was not allowed into Sean "Diddy" Combs’ celeb-laden New Year’s Eve party Saturday.

The charismatic talk show host, according to the NY Post, was turned away by Combs' security when she showed up to the Ciroc bash on Miami’s Star Island with six pals.

Among the stars who did get into the swanky bash included Rihanna, her ex Matt Kemp, Vivica A. Fox, Nelly and couple Robin Thicke and Paula Patton.

A rep for Combs told the paper he was “completely unaware” what had happened and felt "terrible" about it.

As Donald Trump can attest to, Rosie O’Donnell is a fierce foe, and the comic proves she's as sharp-tongued as ever on her new talk show Friday, responding to David Letterman's not-so-nice comments about her recent whirlwind engagement to 40-year-old businesswoman Michelle Rounds.

In his monologue on Tuesday's edition of The Late Show, Letterman said of Rosie's new-found love: “The woman she is marrying, her fiancée, was driving … and her car broke down. And guess what happened? Rosie pulls up right behind her in her tow truck.”

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The power of social networking has impressed Rosie O'Donnell.

After the charismatic talk show host told her studio audience Monday she’d gotten engaged to her girlfriend of three months, someone tweeted it and before long, it was worldwide news.

"You know, I'm engaged, the audience hears, and somebody tweeted it ... by the time I got home it was everywhere -- everywhere!" Rosie said on her show Tuesday. "Not just the tabloids, but the CNN crawl!"

Responding to well-wishers on the social networking blog late Monday, Rosie wrote she was “so so so happy,” posting a pic of the jewel resting on her the finger of her fiancée, 40-year-old businesswoman Michelle Rounds.

Never hesitant to make her personal life public, Rosie O'Donnell tweeted Monday night a pic of the engagement ring she gave to her girlfriend of three months, Michelle Rounds.

Responding to well-wishers on the social networking blog, Rosie wrote she was “so so so happy,” along with a pic of the jewel resting on her fiancée's finger.

As we previously reported, when they first met, Rosie said she didn't plan on making romantic overtures toward Rounds, actually thinking she was straight.

Rosie O’Donnell is engaged to her girlfriend Michelle Rounds and RadarOnline.com has exclusively learned she already has the thumbs up from her kids.

According to a source, Rosie told her studio audience during a taping of her Rosie Show on Friday that she and Michelle would be exchanging vows over the Christmas holidays, Us Weekly reports .

After striking up a conversation with Michelle in a coffee shop just three months ago, the 49-year-old comedian has already fallen fast for the blonde beauty.