Ava Windt leapt into Nicole Segalini's arms when she saw the EMT recently for the first time in over a year. Their relationship goes back to the beginning, literally.

Segalini delivered Ava on a cold March night nearly five years ago. The volunteer first responder — a high school senior at the time — was just months removed from learning how to deliver babies when she got to try the real thing.

That emergency launched a friendship between total strangers that has lasted through Segalini's four years away at college, a major surgery and the pandemic.

Segalini and the Windt family — Ava, big sister Alexa and parents Angela and Paul — reunited recently for dinner so Ava could see the person she knows as "the first one to hold me."

"It was awesome because that's someone who needs to be in her life forever," Angela Windt said.

Windt didn't know any of this would transpire when she was lying on the wooden bedroom floor of her suburban New Jersey home the night of March 10, 2017.

She just knew her second child was coming, and they wouldn't make it to the hospital.

Segalini and two other emergency medical technicians from the Berkeley Heights Volunteer Rescue Squad arrived and hurried into the room after a police officer outside told them that Windt's water had broken.

Segalini began taking Windt's vital signs when she glanced down and her eyes grew wide. She saw the baby's head.

A mix of nerves and calmness settled in as the teen went to work, with the two EMTs who helped train her watching. First, she reassured the Windts.

"I was like, 'Don't worry, I've done this before,' " she said. "I just didn't clarify that I had done it with a plastic baby."

Minutes later, Ava was born. Segalini guided her out, clamped the umbilical cord and wrapped her in a blanket. The baby cried immediately.

On the way to the hospital, Windt learned that a teenager had delivered her daughter.

"There was not an ounce of fear in her," Windt said.

The family visited the EMTs a week later to drop off cupcakes and say thanks, and their relationship began to grow.

Segalini and her family attended Ava's baptism. The three EMTs brought a Build-A-Bear with Ava's name on it to her first birthday.

Segalini started babysitting for the Windts when she came home on break from Lafayette College, and Angela brought her daughters to visit her at school.

In early 2019, after a surgeon removed a benign, softball-size tumor from Segalini's pancreas — something she found doing her own abdominal exam — Angela came over to visit.

Once the pandemic hit, the families stopped getting together in person but traded texts. Windt sent Segalini pictures of the girls. Ava wished her a happy birthday by video.

Then in late October, Segalini stopped by the Windts' home for a dinner of cilantro chicken and rice, coincidentally on National First Responders Day.

Segalini graduated from Lafayette in May with a neuroscience degree, and the 23-year-old's life is currently at a post-college crossroad. She's working for a drug company while she waits to learn whether she got into medical school.

She says she wants to become a complex surgical oncologist after she was allowed to shadow the surgeon who treated her.

Segalini figures she has wanted to be a doctor of some sort since she was around Ava's age. While she waits for her future to sort out, Segalini hopes to see the Windts some more.

She thinks the families have clicked in part due to a common interest in medicine. Paul and Angela are both pharmacists working in drug development. Segalini's mom and Angela Windt also have become friends, and Nicole has a big fan in Alexa, 10, who wants to be an EMT.

Alexa was asleep during the first and only baby delivery that Segalini has performed so far, and Ava is too young to fully understand their connection. But she knows enough, her mom says.

"We tell Ava that she's a very special person for (her)," Windt said. "She understands that."