She's "amazing Gracee" to her parents and family. But little Gracee Broom is becoming better known as "the million-dollar baby."

Her unexpected Feb. 12 arrival at 24 and a half weeks, while her parents were on the "honeymoon they never had" in the US, has left her Aussie family facing massive medical bills that could cost more than AU $1 million (US $1.03m).

The tiny girl is now at the center of an international wrangle between parents Brett and Sonja Broom, their insurance agency and the Australian government.

Insurance giant AAMI is refusing to pay Sonja Broom's medical bills because they say she had a "pre-existing condition" pregnancy. Brett Broom said AAMI told them that Gracee was not covered by their policy because she did not exist at the time of cover.

But even if well enough to travel, Gracee will not be allowed home until she has a visa, which could take months. Because she was born in the US, she is not an Australian citizen.

Husband Brett, a painter, has had to return home to Brisbane to look after their two sons, three-year-old Jack and 22-month-old William, who were being cared for by their grandparents while their parents were overseas.

Sonja Broom has had to stay in Orlando to be with her daughter at the Florida Hospital for Children. But because of Gracee's fragile condition, it is unlikely Sonja Broom will be able to return to Australia with their new daughter until at least July.

"It's been really hard," Sonja Broom said via Skype. "I feel so lonely because there is no one here to turn to. But the good news is she [Gracee] is doing really well. She's a fighter."

The tiny little girl weighed 27 ounces (765g) when born and has doubled her weight to 3.5 pounds (1.59kg) at 32 weeks.

The Brooms had flown into Los Angeles from Brisbane and were on a three-day cruise when the mother-to-be became unwell.

Hours later her waters broke and soon she began having contractions. The ship was already on its way back to Cape Canaveral and Sonja Broom managed to hold on until they reached the mainland and she was taken to the hospital.

The bill for Sonja Broom's three days of care at the hospital was AU $30,000. The couple have paid AU $10,000 towards this as a sign of good faith. Gracee's care is about AU $5,000 a day -- not including doctors' and specialists' fees.

Gracee's bill has already reached AU $300,000 and she is expected to be in the hospital for a further 60 to 80 days.

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