BETHESDA, Md. Her father was playing a members-only event at Congressional Country Club, but the Penn State freshman-to-be had to slip away to find her new favorite player on the PGA Tour.

Jordan Spieth is No. 1 now, especially since Adam Scott's April wedding, she said. So when Spieth posed for a picture near the putting green before the Quicken Loans National last month, her friends probably saw it on Instagram within seconds.

Spieth, who turned 21 this weekend, seemed unfazed by the attention. He's dating his high school sweetheart, Annie Verret, but she's not the only important female in his life. He draws inspiration from his sister Ellie, a special needs teenager who is seven years younger than Spieth.

When Spieth captured the John Deere Classic last year two weeks shy of his 20th birthday, he became the youngest winner on the PGA Tour since 1931 and the fourth player under 20 to win on the tour since 1900. He was a captain's pick for the U.S. Presidents Cup team, earning him a chance to play in his first World Golf Championships-Bridgestone Invitational this week at Firestone Country Club.

Turning pro after two years at the University of Texas, Spieth became the first player since Tiger Woods to begin a season without tour status and finish it in the Tour Championship. He accomplished the feat about eight months younger than Woods. Spieth not only made it into the FedExCup finale at East Lake in Atlanta, but he also tied for second.

During his phenomenal rise, older peers have marveled at Spieth's lack of pretension and wisdom beyond his years.

"He came up through the amateur ranks ahead of my son, so I've always been impressed with everything he's done," Davis Love III said last fall at the Presidents Cup. "He says the right thing, does the right thing, fits right in. 1/8My wife3/8 Robin said, 'He just walked in the room like he belongs.'

"Every time I've been around him, great things happen. So I'm trying to hang around him as much as possible. I'm sitting by him at dinner."

Spieth said his down-to-earth nature and comfortable presence comes from the way his parents raised him, Ellie and brother, Steven, who plays basketball at Brown University. They grew up in a middle-class neighborhood in Dallas. Father Shawn, who played baseball at Lehigh University, worked at Alcoa, got his MBA and moved on to a social media startup, according to Golf Digest. Mother Chris, a basketball player at Moravian College, was a computer engineer who worked at Neiman Marcus for 17 years.

"Me speaking about humility is very difficult because that wouldn't be humility," Spieth said last month before the Quicken Loans National. "My parents, they've never been in this kind of position, but they've always at each level told me to set goals for myself. I set extremely high goals. It's very humbling because I still haven't accomplished most of the goals I set for myself as a pro."

When Spieth needs a reminder of how fortunate he is, he doesn't glance at the $7.6 million he's earned in 2013-14. He can think of Ellie.

"Ellie certainly is the best thing that's happened in our family," Spieth said. "It helps put things in perspective that I'm lucky to play on tour and to compete with these guys, it's been a dream come true. I definitely attribute a lot of that to her."

Spieth used to bring Ellie key chains from every city in which he played, but he said she's tired of that now.

"Now when I get home she wants me to take her to the store," he said.

Ellie has also provided a bond for Spieth with Ernie Els, whose autistic son, Ben, prompted him to establish the Els for Austism Foundation in 2009. Spieth plans to turn the Jordan Spieth Charitable Trust into something similar to spread awareness.

"I've played with him quite a few times and we've spoken about his family and how they have coped with their situation," Els said at Congressional. "We've shared some really funny kind of stories because autistic kids are so special, and the way they handle life is quite special.

"If I look at my own daughter, Samantha, growing up with a brother that's autistic, they look at life a little bit differently. They see how special and how honest and how loving these kids are. They do grow up with a little different perspective to life. I think there's maybe a bit more appreciation."

His sister and family values might keep Spieth from getting too caught up in believing he's the next big thing, no matter what the numbers say. He's played in 52 tour events and made 42 cuts, with five seconds, 16 top 10s and 31 top 25s in his career.

"He's at the top of the list of the younger guys who are really bringing the game to the fore," Els said at Congressional. "He's got an old head on young shoulders. He understands the game at a young age. He's cocky enough that he knows he's good, but he doesn't think he knows everything. He's ready to learn. I like his competitiveness."