Above that were three gold stars to reflect her updated total of major championships: There's the one she won Saturday at Flushing Meadows and the pair from the French Open in 2020 and this June (when her pullover sported two stars).
If Swiatek keeps playing and performing like this, if she manages to remain healthy and grounded, they're going to need to keep making new jackets for her.
Still just 21 yet already guaranteed a spot on the International Tennis Hall of Fame ballot five years after retirement, Swiatek is quickly establishing herself as a player no one wants to face. Especially in a final.
Her 6-2, 7-6 (5) victory over Ons Jabeur in Arthur Ashe Stadium on Saturday gave Swiatek 10 consecutive triumphs in title matches, every one in straight sets.
And to think: This is not her favorite surface, her favorite tennis balls, her favorite weather, her favorite site. Each of Swiatek's past three trips to New York had ended with third-round exits. She arrived this time with few expectations and zero idea that it would be a two-week stay.
Which just all makes it that much more impressive.
Plus, as big as her forehand is, as skilled a returner as she is — winning half of Saturday's 10 games served by Jabeur, who didn't face a single break point in the semifinals — as speedy and full of anticipation as her get-to-every-ball court coverage is, it's Swiatek's ability to think her way through the crucible of a match that might be her most valuable ability.
“I'm proud that I have much more solutions and options on court than I had before, tennis-wise, but also mentally.
"I'm using these skills pretty well. I'm really proud of that, because I just know how it feels to not have ideas on court, not have anything you can change to make the match better,” said Swiatek, the first Polish tennis player to win a Grand Slam singles title.
“Right now, it's been a long time since I didn't have any idea. So that's great. It shows that I'm actually doing progress.”
That's daunting for everyone else in the game.
“In the key moments, Iga plays a little bit better,” said Arantxa Sánchez Vicario, who counts the 1994 U.S. Open among her four Grand Slam singles titles and was advising Jabeur during the tournament.
“Iga is just amazing. She has a lot of confidence and everyone knows she's the top player right now on the tour.”
Swiatek is 55-7 with seven titles in 2022.
She's now shown she can win on the red clay of Roland Garros and on the hard courts, and amid the hubub, of Flushing Meadows.
“I feel like she improved a lot from last year until the beginning of this year,” Jabeur said. “She's, I think, working on a lot of things that get in her way.”
So there is little reason to diminish her chances on hard courts at the Australian Open, where she made it to the semifinals in January, or even on the grass at Wimbledon, even if she hasn't been beyond the fourth round there.
Asked what she's most excited about as she thinks about the future, Swiatek said she wants to see how, or whether, anything will be different now.
There will be more attention on her. There will be more away-from-tennis distractions.
“I'm going to see how I'm going to react,” she said.
“Winning the U.S. Open is different than winning a Slam in Europe or in Australia, because I don't know how the popularity thing is going to change, if it's going to change.”
Then, with her latest trophy sitting in front of her, Swiatek offered this thought: “For now, I'm kind of going to observe and learn. For the future, I know I still have a lot to improve on court. That's something that I'm excited for, because maybe it's just going to get easier to play these matches.”
Easier? Look out.
Swiatek said this championship showed her “the sky's the limit.”