She grew up in Santa Clara, California, and played indoor volleyball at Stanford, where she was a two-time All-American and helped the Cardinal compete at the national level. The transition from indoor to beach is not automatic — the two games share a net and a ball and diverge in almost every other respect, from court size to team structure to the physical demands of playing on sand without substitutes. She made the transition and found a partner in May-Treanor whose defensive instincts complemented Walsh Jennings's blocking and attacking at the net in a way that proved, across a decade of competition, essentially unsolvable. At the 2012 London Games she competed with a torn rotator cuff that had been surgically repaired months earlier, wearing a black patch on her shoulder throughout the tournament. They won gold. She returned for the 2016 Rio Games with a new partner, April Ross, after May-Treanor retired, and won bronze, her fifth Olympic medal across four Games.

She married fellow volleyball player Casey Jennings in 2005 and they have three children. She has spoken extensively about competing through pregnancies and returning to elite competition after each, treating her physical resilience as something she has been deliberate about documenting publicly for other athletes. She attempted to qualify for the 2020 Tokyo Games and has remained connected to the sport through her p1440 volleyball organization, which she founded to expand the professional beach volleyball ecosystem in the United States.