ABOARD MITT ROMNEY'S CAMPAIGN PLANE — Despite facing the speech of her life within hours, White House hopeful Mitt Romney's wife Ann had her warmth and charm on display Tuesday as she wooed reporters aboard his jet.

While Mitt often appears stiff and awkward as he interacts with voters and the media, the Republican challenger hopes Ann can show off his warmer side at this week's Republican National Convention in Tampa, Florida.

Ann Romney's speech introducing her husband was keenly anticipated, but she was all smiles as she left his side to stride to the back of his campaign plane to chat with reporters and share some of her home cooking.

"I baked these today, they're fresh," the 63-year-old said, holding out a round tin of Welsh cakes. "These are my grandmother's recipe."

That said, the woman charged with adding a human facet to Romney's tightly focused campaign admitted that she had fiddled with the matriarch's treasured recipe in order to make the cakes "much more moist and delicious."

Did she have any nerves or anxiety about her speech to America?

Apparently not, as she quipped that her remarks had been "reduced to a tweet" and that she was more anxious about what she would wear than what she would say to millions of Americans during prime time.

"The funniest thing of all is that Stuart Stevens, who wears his shirts inside out, is advising me on what dress I should wear tonight," she said, referring to a senior Romney strategist.

With reporters quizzing her about her fashion choice, she confided that "the verdict is still out on what I'm going to wear... It was going to be like my wedding day, he wasn't going to know what I was going to wear."

Ann has known Mitt Romney since they attended neighboring private schools in their home state of Michigan and the couple married in 1969 after he returned from two years of missionary work in France for his Mormon church.

They had five sons together between 1970 and 1981, and the public face of their relationship has always been that of a close and happy partnership, to the point that some critics mocked her perceived subservience.

In 1998 she was diagnosed with the degenerative disease multiple sclerosis, a turn that Romney has described as the worst day in his life.

"I couldn't operate without Ann. We're a partnership. We've always been a partnership, so her being healthy and our being able to be together is essential," he later told the Boston Globe.

The progression of the disease was halted -- Ann credits a variety of medical and complementary therapies -- and she survived to become first lady of Massachusetts during Romney's 2003 to 2007 governorship.

She is also known for her passion for horse trials, and this year had a mount in competition in the dressage event at the 2012 London Olympics -- a fringe event that many mocked as a symbol of the couple's wealthy lifestyle.

On Tuesday, the Romneys had spent much of the previous two days in New Hampshire doing heavy-duty speech prep with Stevens, and Ann acknowledged she had "never given a speech like this before, but I'm excited."

Her remarks were slated for 10:00 pm Tuesday (0200 GMT Wednesday) on the first night of a storm-shrunken Republican National Convention, and they have been tweaked, massaged and revised.

But odds are it will not be cleansed of Ann Romney's disarming charm and her ability to present a more personable side to her husband, a multimillionaire businessman who has never really won over public affection.

"You will see that my speech is heartfelt, and I think a lot of you have been covering me long enough and you know that I've never gone off of a written text," she said.

"So this is a unique experience for me to actually have something written."

Romney has hit the stump with her husband dozens of times on the campaign, and she is received more warmly than the candidate, as people embrace her story of personal difficulty in overcoming multiple sclerosis.

On the flight to Tampa, Romney remained in the front of the plane huddled with strategists like Stevens leaning over to advise him, while Ann was up and about entertaining staff and the travelling press.

But she also found time to consult on details of her upcoming address.

"There is not a line I need to tweak, but we are refining it up there," she said, explaining that the experience of reading a prepared and vetted campaign document off a teleprompter in front of a vast crowd would be a new one.

"I've had a lot of input in this, I must say, and a lot of tweaking where I felt like I was getting what I really wanted to say from my heart," she said. "I've never spoken with a teleprompter either. I don't like it. It's hard."