BEDMINSTER, N.J. — There they all were, standing three in a row, as the sun fell below the horizon and the ball fell toward the green.

On the left was 13-year-old Anna Heck. On the right was 18-year-old Abby Heck. In the middle was their mother, Stacy Heck, and that falling ball belonged to Rachel, their 15-year-old sister and the youngest player in the U.S. Women’s Open field this week.

“Oh, my God,” Abby whispered, looking at her mom, as Rachel’s approach shot stuck no more than 10 feet from the third-hole flag Thursday evening. “Oh, my God.”

In a round full of firsts and surprises — Rachel’s first tee shot at a major, Rachel’s first birdie at a major, a two-hour weather delay, a suspension of play that forced Rachel to resume at 7 a.m. Friday through thick rain, putting nearly 18 hours between her first and last shots of the round — this is when it seemed to all click for the Memphis family.

Rachel wasn’t just playing in the U.S. Women’s Open. She was thriving in it.

“Mom! Mom!” Abby whispered again, this time a bit louder. “Oh, my God!”

Stacy didn’t flinch. Her eyes stayed fixed on the ball.

Her daughter would finish the round Friday morning with an even-par 72 before starting her second round 45 minutes later. Rachel shot 74 to finish the day at 2-over 144 for the tournament and make the cut right on the line. Shanshan Feng shot a 70 to maintain her two-shot lead over three players at 8 under.

Stacy hung on to every shot with clenched fists and quiet, unbending hope. They all did.

Being the youngest player at the U.S. Women’s Open is exhilarating and nerve-racking and unpredictable all at once. Being in that player’s family is not much different.

“I honestly have no clue what’s going to happen out there,” Rachel said Wednesday after her final practice round before the tournament. “But I do have one prediction: I think my family will be more nervous than me.”

No. 10 to No. 14

Just before Rachel teed off from the 10th hole at 2:42 p.m. on Thursday, she glanced over at Abby and subtly smiled.

She was trying to play it cool as her name was announced — “Rachel Heck, amateur from East Memphis, Tenn.” — and having her sister there helped. Abby will start her collegiate golf career at Notre Dame in the fall. Rachel, who just finished her freshman year of high school, is committed to begin hers at Stanford in three years. Being on the golf course together is as comfortable as they get.

But Stacy didn’t watch the first shot from up close. She was already walking down the fairway as Rachel, who won a qualifier in Braselton, Ga., to become one of 21 amateurs in the field, teed off. Call it muscle memory.

“I’m usually the only one around to mark where the ball goes,” Stacy said, still moving down the fairway. “I guess at an event like this they have people who did that for you. Man, I need to get used to being at the U.S. Open.”

They all had to pinch themselves at one point or another. On Tuesday, Rachel was on the practice putting green with Michelle Wie and other professional players she’s been looking up to for years. She knocked around putts while stealing glances at the players around her.

Robert, her father and this week her caddie, walked onto the green and leaned into her ear.

“Pretend like I’m giving you advice,” he whispered. “I just wanted to come stand out here with you.”

Now they were walking down the 10th fairway, side-by-side, as Stacy, Abby and Anna followed from behind the ropes. Two friends from Memphis and Rachel’s coach were also with them. They mostly whispered to one another, like a family that spends a lot of time around golf courses.

And then they clapped lightly as Rachel shot par at 10, 11, 12 and 13.

“Birdies are great, but I’ll take tap-in pars all day,” Stacy said as she speed-walked to the 14th hole. “I just need like one more hole and I’ll be fine. I’m fine. I just need one more hole and I’ll really be fine.”

No. 14 to No. 18

Stacy’s and Abby’s phones didn’t stop buzzing all afternoon.

Then it happened. Rachel was on TV for the first time.

“Oh, my God, everyone is texting me that they just saw Rachel,” Stacy said, beaming into her iPhone. “She was in the background of a shot of Nelly Korda. I imagine she will be in the background most of the day.”

The texts and videos and Snapchats kept rolling in from there. Friends and family sent photos of Rachel’s name on the leader board, videos of her group teeing off and images of the old photo the U.S. Golf Association used on its scoring site. It is from when Rachel was 13 and had braces. Her friends had a field day with it.

But Stacy, Abby and Anna always looked up as Rachel wound up for a shot. All three of their heads leaned back in unison, and their eyes squinted to find the ball in the pale-blue sky. Then one of them would deliver a verdict, always in a hushed voice.

“Well, it’s not terrible,” said Anna, the youngest, for an approach shot that fell well short of the pin. Rachel tapped in for par two shots later.

One hole later, she knocked in her first birdie as thunder sounded in the distance. Horns blared as she walked from No. 15 to No. 16, signaling a weather delay. Rachel could have been nervous about her next task, a daunting tee shot at the par-three 16 that goes straight at a big body of water. Instead she spent the two-hour break begging her mom to get the USGA to change that embarrassing photo.

“I couldn’t stop thinking about the first shot at 16,” Stacy said. “Like, ‘Oh, my God, she has to do that after a break?’ No way. But she didn’t think about it at all.”

Rachel nailed the drive, sticking the ball 12 feet from the hole. Again, she tapped in for par. Then she birdied 17 and 18, the latter coming with rain pouring out of a gray sky. Stacy, Abby and Anna didn’t say a word about Rachel’s score dipping to 3 under. They instead discussed it silently, looking at each other for long stretches, eyes wide, mouths still.

Their phones kept buzzing. Rachel was on TV again. Except this time she wasn’t in the background. The commentators were talking about her.

“Your daughter is going to be on ESPN tomorrow,” a man said after Rachel birdied 18, and all Stacy could do was smile and nod.

No. 1 to No. 9

Now they all begged for daylight.

Rachel was in a rhythm, but it was getting dark fast, and they all wondered how many holes she could get in before tournament officials called it a day. After each shot, Stacy looked into the sky to find the sun. Soon it was behind a line of trees, and then it was gone.

“Well, at least she’ll leave knowing she had a great day,” Stacy said at 8:30 p.m. Thursday. “And maybe she’ll get some sleep.”

“We’re going to get no sleep,” said Anna, her shoulders slumped from all the walking. “Rachel woke me up so early this morning.”

They got in four holes before the horns blared again, and Rachel parred them all. Twelve fans were left watching the group. Six of them were for her. Rachel’s approach shot at the third hole left Abby whispering “Oh, my God” into the quiet dusk. The day left them exhausted and in slight disbelief.

“I didn’t know what to expect at all,” said Robert, his daughter tied for sixth overall at 3 under through 13 holes at the end of Thursday. “But I don’t think I expected that.”

Rachel’s alarm went off at 3:30 a.m. Friday, and the Hecks were at the course an hour later. Rachel finished the round with mixed results: a bogey, double bogey, birdie, par and bogey, good for an even score and chance to make the cut at day’s end.

Her second round started just 45 minutes after the first ended. It offered 18 more holes to decode. Eighteen more holes for her family to walk, pleading for good shots and low scores. But it would likely all be a bit easier a second time around.

By that point, they were all pros.