Heather Coles and Elisabeth Carbrey welcomed premie babies at Sister's Hospital less than three months ago.

They came back Tuesday, babies in tow, to help other mothers...by donating breast milk.

"When the twins were born, I was worried about having enough milk just for the two of them," Heather said. "So we were like praying for a double portion of milk and then I got so much milk that I realized I had enough to feed like the whole NICU."

Heather delivered twins at 27 weeks. Elisabeth delivered a daughter at 30 weeks.

Even though they both delivered early, their bodies are producing enough milk for their babies and then some.

Thanks to the New York Milk Bank, none of that milk will go to waste.

"If I hadn't been able to pump milk, I would have really wanted her to have human milk because I believe that's the best for her," Elisabeth said. "You know science shows that that's the best for babies and especially being early. For her to have milk that was made for a baby who was early really would have been important to me."

The New York Milk Bank hopes other moms, with enough milk, will feel the same.

The state's bank opened just about a year ago this Mother's Day.

To be a donor, moms have to go through routine health checks and then are given a donor number. They can then pump at home and donate to any of the drop-off sites, like Sister's Hospital, whenever they have enough stored up.

"There are NICU babies, premature babies, born every single day that need this milk and there are illnesses like necrotizing enterocolitis that can be life or death for these children and human milk coats that baby's belly and gives them all the antibodies they need to help prevent this illness from happening," Gina Harman, the lactation coordinator for Sister's Hospital, said.

Up until the New York Milk Bank opened last year, any milk donated from moms was sent out of state. Now it stays right in New York.

Harman said she sees the need for milk, first hand, especially in the hospital's NICU.

Plus, there is a unique need for breast milk from these moms of preemies.

"The beautiful thing about that is breast milk is always changing," Harman said. "Instead of a mom maybe that delivered or maybe has a baby that's one years old, her milk is different than these girls that have babies that are six weeks old."

If it can't be the biological mom's milk, Harman said the next best thing is the milk from another mom.

"That's just really special and important to me to be able to share the access that we've been blessed to have," Elisabeth said.