The news that Aleta St. James – a woman two days shy of her 57th birthday – bore a pair of healthy twins sends an important reminder to 30-something singletons: Biological clocks are for sissies.

Though there are health risks, women with enough money, physical fitness, and determination can have babies no matter their age.

“You have to really want children,” said Ms. St. James at a news conference yesterday. “It’s not over when you’re 50. I’m winding up, not winding down.”

Ms. James, who had in vitro fertilization, looked radiant and healthy as she spoke to reporters at Mount Sinai Hospital on the Upper East Side. Her hair and makeup were perfect. She had friends and family – including her brother Curtis Sliwa, founder of the Guardian Angels – present. There was no man to speak of, but with tiny Francesca and Gian in her arms, this mother was positively triumphant.

According to her reproductive endocrinologist, Dr. Jane Miller, these babies took some serious work to create.

“She’s the oldest patient I’ve taken care of. She came to me at 53. This was a long time in coming,” said Dr. Miller.

What made Ms. St. James’s pregnancy possible was her overall level of fitness. “She exercises a lot, eats well, and meditates,” said Dr. Miller.

And though the babies were born by Caesarian section, it was only necessary because of their position.

“She is fit enough that she could have had a vaginal delivery,” said Dr. Jonathan Scher of Mount Sinai School of Medicine.

The news is comforting for those who are putting off childbearing.

“As a young business owner I don’t foresee having children in my near future,” said Gabrielle Bernstein, 25, owner of SparkPlug Communications. “I have other plans for myself and my career.”

Ms. Bernstein knows the reality of new developments late in life. “My mom is remarried. She met her husband onmatch.com and has a whole new life at 55.”

Daniella Brodsky, author of “The Girls Guide to New York Nightlife” and “Diary of a Working Girl” also cheers on women who want determine the paths of their own lives.

Though she’s in her late 20s, she has a 6-year-old brother. And her mother’s surprise pregnancy transformed the lives of her family. “It was such a blessing to our family. It gave our lives such an enhancement.”

Using Ms. St. James as an example of the choices open to women, Ms. Brodsky said: “You can do whatever you want. If you want to meet someone, you’ll do that. If you want to be depressed and lonely, you’ll do that, too.”

But even if you want to have a baby at 56, you’ve got to have the money.

Though Ms. St. James did not give a specific dollar figure on how much her two attempts at pregnancy were, the average cost for one in vitro process can be about $12,000.

“Women have their own businesses, and they can afford to take of children,” said Cindy Barshop, owner of the hightech spa Completely Bare. “Women are taking care of themselves.”

But what do the men have to say?

“A 56-year-old woman having a baby just added a decade to men’s ‘We have plenty of time’ speech,” said David Spiecher, 30, who lives in Brooklyn. “My mother just turned 56, and I wish she’d have another baby. She’d leave me alone for a day or two.”