THE PARENTS: Kelly Kapp, 30, and Jon Kapp, 30, of Ambler

THE CHILD: Caroline Anne, born May 31, 2018

AN EARLY RELATIONSHIP TEST: Cohabiting in a converted office-bedroom in South Philly, a room so small they could get out of bed on only one side.

It was supposed to be a surprise: a 28th birthday party for Jon, planned on the down-low by Kelly with help from Jon's pal in San Diego.

But Jon had an even stealthier plan in mind. On that February 2016 weekend, he took Kelly to the Philadelphia Museum of Art, then hailed a cab to Center City. They rode the elevator to the top of One Liberty Place; there, he proposed in view of the sunset, followed by drinks and a lavish meal.

Then he said he wanted to go home.

Kelly, still believing she was in collusion with Jon's pal, insisted on one more stop. At Castle Roxx in Manayunk, 85 people were waiting — not to cheer Jon's birthday, but to celebrate the couple's engagement.

When they walked in, "I wasn't totally blindsided with people being at the bar," Kelly says. "But I was surprised."

It was a theme of their relationship, which started with a three-week romance just before the end of the year at Pennsylvania State University. He thought she was smart and responsible; she was drawn to his humor and gregariousness. Both were rabid sports fans, though she cheered for the Giants and he was an Eagles devotee. Both adored their alma mater.

Still, she figured graduation would be a natural stopping point. "I had a job lined up, and Jon was still working on his postgraduation plans. I had planned on ending the relationship. But on graduation night, I realized I didn't want to."

Instead, Kelly took her accounting degree and moved to Manayunk; Jon lived with his father and stepmother in Fort Washington, then with friends. He describes that stretch of their relationship as "training camp."

"I spent a lot of time with Kelly, hanging out with her friends. She put up with me," he says. That remained true when Jon worked long, erratic hours at a car rental agency and, while at home, watched endless hours of televised golf.

Their May 2017 wedding included a few more moments of surprise and recovery: when Jon, in a rush to get ready, shattered a small bottle of Cartier cologne (he managed not to slice a finger in his attempt to tap a few drops of the cologne on his neck), or when the trolley that was supposed to transport the wedding party broke down. "I went to my wedding in my dad's Camry," Kelly says with a laugh.

They wanted children, preferably soon; Jon was infatuated with his 8-month-old nephew, and Kelly, the oldest of six, had always envisioned being a mom. Still, they felt a little sideswiped on that Thursday night, just four months after their wedding, when Kelly blurted, "I need to tell you something," and held out a positive pregnancy test.

Jon's first thought: Don't say anything stupid.

"It was an emotional moment," he recalls. "I said, 'We'll be OK. We're married. We'll be great parents.' "

In the coming months, he surprised himself with sudden determination for housecleaning (and house-hunting), for reading about environmental hazards and how to create a healthy home for a child.

In the meantime, Kelly was having an easy ride of a pregnancy — aside from exhaustion, even when she slept a prodigious 12 hours per night, and a craving for a favorite childhood treat, Smidgen peanut butter cups. Her hopes for the delivery were straightforward: a healthy baby.

"I'm pretty type A and tend to micromanage situations, but in this instance, I didn't want to have too many expectations," she says. "I had to be open-minded that anything could happen."

What happened was that her water broke 10 days ahead of her due date; the couple had bought a car the day before to replace Jon's 1998 Jeep Cherokee, and the car seat wasn't yet installed. On the way to Abington Hospital, Jon recalled one gem of advice from a dad friend: When you're driving to the hospital, and there's a yellow light, just keep going.

In the delivery room, labor moved slowly enough that they had time to watch a few episodes of The Office. And by the time Caroline Anne, named for her grandmothers, arrived at 5 a.m. the next day, Jon was so stunned he just stared at his daughter instead of calling out the baby's sex as planned.

"The doctors were saying, 'Dad, what is it?' I said, 'I think she's a girl.' Everyone was laughing. They took her right over to the warmer, and we heard her cry."

"I just remember looking at her face, and my heart exploded into a million pieces," Kelly says.

These first months, they say, have been a lesson in corralling expectations — of each other, and of their daughter. Kelly imagined having a regular, daily respite when the baby napped from 1 to 3 p.m. "But that's not how things go. She's going to eat when she eats and sleep when she sleeps."

The first weekend after Caroline was born, Jon eagerly fetched a toy — one of those small stuffed creatures with a bell and crinkly wings — thinking his infant daughter might want to play.

And then there was the night — Caroline was five weeks old — when Kelly went out with girlfriends for the first time postpartum. Jon figured the baby would sleep while he played video games and changed the occasional diaper. "But she didn't sleep at all. I walked her around the house, put her in the bassinet, did 30 or 40 laps in her stroller around the first floor. Kelly called, and I said, 'This isn't a good time.' "

It's all become easier: the feeding, the sleeping, the soothing. Kelly and Jon have a bit more bandwidth to pay attention to each other. And there are new surprises — such as the other day, when they were singing "Row, row, row your boat" to Caroline and she began to giggle. "Merrily, merrily, merrily, merrily; life is but a dream." By the end of the song, she was laughing out loud.