(Paul Sancya/AP Photo)

SARASOTA, Fla. - Rick Santorum's eldest daughter, Elizabeth, took his place at a campaign rally here today while he remained in Philadelphia with his hospitalized daughter, Isabella.

"We do what we do as a family. We stick together and we get through and we are hanging in there," Elizabeth Santorum told reporters after the event.

Bella, as the family calls the 3-year-old, was admitted to Children's Hospital of Philadelphia Saturday night with pneumonia in both of her lungs. She suffers from Trisomy 18, a rare and serious genetic disorder, which kills about 90 percent of children before or during birth.

When asked about the latest update on her sister's health, Elizabeth declined to give details.

"She got sick and right now she's in the hospital and we're hoping and praying she will be better soon," she said.

She said her father "will be back as soon as he can" campaigning in Florida, but "right now family comes first, being a dad and being a husband right now, so that's why he's home."

The campaign rally in an airplane hangar here began with a prayer and moment of silence for Bella.

Elizabeth, 20, addressed the crowd briefly saying her father "wishes he could be with all of you today," but he is "exercising his most important role, which is being a dad."

"I think back now many months ago, this has been quite a journey and I look back and think of the many nights around our kitchen table when we would talk about starting this journey," Elizabeth Santorum said to the crowd of about 250. "We knew from the very beginning that this would not be easy, this was not the easiest course for our family. We knew there would be hard moments that would test us and try us, but we knew that this would be worth it because America is worth it."

The event wasn't without politics, though. Joining Elizabeth at the rally were several of the Duggar children from the TLC show, "19 Kids and Counting."

The eldest, Josh, railed against two of Santorum's opponents, Newt Gingrich and Mitt Romney. He said Gingrich supported an individual health care mandate for "over 20 years" until "he realized I'm going to run for office so I probably shouldn't support 'Obamacare,' that wouldn't be a good idea. When it is politically advantageous he's changed his position on things."

He said Romney's health care plan in Massachusetts "included a $50 co-pay for abortions."

He added that while governor, Romney "issued a declaration saying homosexuals and homosexual lifestyles should be encouraged."

Duggar gave no details about what declaration he was talking about. Romney has consistently said he is against same-sex marriage, but he does not believe gay people should be discriminated against.

Rick Santorum often mentions Bella and her diagnosis on the campaign trail, stressing that he entered the race because of President Obama's health care legislation, which he believes will curb and ration treatment for his daughter and other children like her who need medical care.

The campaign says the former Pennsylvania senator will still participate in two evening tele-town halls with Florida and Minnesota voters and an event at an Orthodox synagogue in Boca Raton is still on the schedule for Monday morning.