After she was dropped off at the curb at Heathrow Airport after the London games, and before she boarded her flight home, she walked by a picture of the Cristo Redentor statue, a famous Rio de Janeiro landmark.
Walsh Jennings, who with May-Treanor has won an unprecedented three-straight Olympic gold medals in beach volleyball, then said she was coming back.
"Aug 18, 2016, I want to be winning a gold medal," Walsh Jennings said. "I know the date, I know where I want to be and I know what I want. All these things are leading up to it."
In 2016, Walsh Jennings will be 38 years old.
"People love talking about age, and I guess it's understandable because I'm playing against mostly 20-year-olds," Walsh Jennings said. "But I feel the way I feel. I have a lot of passion in my heart and a lot of room for improvement. That's what I look at."
"I don't ever want to call myself old, because then I'll start feeling old," she said. "That's illegal in my sport."
Walsh Jennings has three children -- the youngest of whom was born 11 weeks ago. But she's back on the beach in California, training for the World Series of Beach Volleyball, which will be played in Long Beach in July.
She'll play with Whitney Pavlik, a 29-year-old American, and again with an unannounced partner, in the World Series Cup, also in Long Beach.
But Walsh Jennings hasn't decided on who will take the place of May-Treanor as her long-term partner, although the teammates that took the silver medal in London, April Ross and Jennifer Kessy, both make good candidates.
Ross, in particular, could be a good fit for Walsh Jennings' playing style, and the two hope to play together in Long Beach.
"She's a stud," Walsh Jennings said about Ross. " I respect her so much. She's been my main competitor for so many years."
"She's driven me more than any other person so it's going to be so fun to partner up with her," Walsh Jennings said. "It's kind of a lot like Misty. I had so much respect, but she was on the other side of the net. Then we got together and magic happened. I'm hoping and planning that happens with April."
Still, going without May-Treanor won't be easy. It's always been the two of them, Misty and Kerri, Walsh and May.
"It's been Misty and I for so many years," Jennings said. "My first day on the beach, she wasn't there and I kind of shed a tear."
"But that's a beautiful thing. We had something so special that's never going to change," she said. "But this new partnership is such an exciting thing because I'm going to grow because of it, I'm going to be better because of it."