Carter, who won the NCAA title in the 400-meter hurdles in a collegiate record of 53.21 last week in Eugene, Ore., is supposed to be a bridesmaid at her older sister's wedding in the mountains near Claremont in Southern California this August.
Should Carter qualify for the World Championships in Moscow — also in August — her big plans as a member of the wedding party will turn into big plans of a possible world title as a member of the United States track and field team.
"I'm going to be the worst bridesmaid ever," Carter said. "And what is even worse, my sister (Kelly) and I talked about the wedding last year. She knows how involved I am in track and field and when we talked about the date last year I told her I would be free. There was no way to know then how my season would go. I know she is upset about that."
Should Carter shed her bridesmaid role, it perhaps will be appropriate because she's no longer on the outside looking in when it comes to the world of hurdling.
Carter's chances of making it to Moscow are excellent. In winning her NCAA title, she ran the fastest 400 hurdles in the world to this season, spurred on by her competition with Arizona senior Georganne Moline, who finished fifth at the 2012 London Olympics in the event.
Moline also bettered the previous college record in the dramatic race, the fifth time this year the two have been in the same race. Carter has won all five races. There likely will be a sixth encounter in Iowa.
"When I finished the race I went over to her and thanked her," Carter said. "I told her I would not have been able to anything without her. She was my target and my biggest competition. She'd probably say the same thing about me. I think we have a healthy rivalry."
Carter was a virtual unknown commodity when she opened her outdoor season this year in Tucson, Ariz. She finished 24th at the NCAA championships a year ago, running a personal-best 57.60.
When she lined up to run the 400 hurdles for the first time, at the Jim Click Shootout in Tucson, Moline also was making her season debut as the main attraction.
"Going in, all I wanted to do was run a good race," Carter said. "My coach (Jody Stewart) told me 'don't let her win just because she's an Olympian.' I was doing my best to beat her and I didn't realize how fast we were going."
Carter ran a 54.71 to Moline's 54.98, the beginning of a beautiful relationship that she took as a sign her training was going well and she could actually run the event."
"I PR'd by three seconds and beat an Olympian on her home track," Carter said. "That made it clear I was on the right track. After the race, (Stanford teammate) Kala (Stepter) said she was so far behind she thought she was running her worst race."
Carter, who finished second in the 100 hurdles (12.79) at the NCAA meet after finishing 14th in the same meet last year, said she was so disappointed in herself about her sophomore season that she re-dedicated herself to the hurdles — the 400 in particular — during the offseason.
"I knew I could have done better," she said. "One of my major goals was to spend more time on the track and in the weight room. A lot of what I did was build up strength. I've been known for coming from behind. That first race we were together coming off the final turn and the line right in front of us. Last year I didn't have a kick over the final 100 meters and would never have won. This year I felt stronger."
She credits Stewart for revamping her training in a variety of ways, from diet to the weight room.
"It's what I wanted," Carter said. "I intensified my work ethic in a lot of different areas and committed to the 400. There were other things, little things, like hitting the weight room before and after practice and not going out as much as I did last year. My top priority was to take it to the next level. I'm working for that elusive perfect race."
Along with being the 2013 world leader in the 400 hurdles, Carter is tied for eighth in the world with her PR of 12.76 that won the Pac-12 title. Carter now ranks No. 6 all-time in U.S. history in the 400 hurdles and is among the top five best combination hurdlers (100 and 400) in this country.
Carter has her parents and siblings to thank for her competitive nature, her toughness and her ability to use her strengths.
She's the youngest of three daughters and has a younger brother Kai. When they played together, the idea was to never give an inch.
"We can't even play Scrabble peacefully," Carter said. "When I played basketball against my sisters (also Kai), I had to learn to toughen up. My dad (Bruce) was the ref and always said 'no foul!' I learned to use my speed. It was the one thing I had."
Bruce and Lena Carter graduated from USC and remain die-hard Trojans fans. At track meets, even while they wear Stanford gear, they only root for the Cardinal if Kori was in the event.
"I grew up with season tickets in the Reggie Bush era," Carter said. "When I was admitted to Stanford, it was when we started smashing USC. It's been great."
Her father drove up to watch the USC game at Stanford in September. The Trojans were ranked No. 2 in the nation at the time. Stanford won, 21-14.
"I'm crashing the field and he's still in the stands, disappointed," Carter said.
When Carter won her NCAA title, members of the football team ("there's a good mix of linemen and defensive players," she said) surprised her with an ice cream cake.
"I try to eat healthy," Carter said. "I eat spinach and drink a lot of water. But every now and then I have to have an In-n-Out Burger. I had a tiny piece of the cake."
In Des Moines, Carter will not only face Moline, but some of the biggest names in women's hurdles — but only in the longer race since she's dropping the 100 hurdles.
"It's so crazy," she said. "When you're little you think about making the Olympics and watching your heroes. All of a sudden I'm in a race with them with a chance of winning. (American recordholder) Lashinda Demus, I have a poster of her on my wall."
Kelly, who played soccer at San Diego State, will just have to understand.