Whakaotihia te rerenga e whai ake nei: I te 2012 Summer Olympics i Rānana, ka pakaru ano ia i tana rekoata Amerika, ka whakaturia he rekoata Orimipia me te wa o 56.25 hēkona i roto i tana 100 mita butterfly qualifying heat. I te whakamutunga o te 100 mita butterfly, i wikitoria ia i te mētara koura me te whakatakoto i tetahi rekoata hou o te ao me tana waa 55.98. I whakataetae hoki a Vollmer i te
4×200-mita relay kāhua-kore. I kaukau ia i te waewae tuarua me te waa o te 1: 56.02, i te wa i wini ai te roopu US i te koura me te waa o te 7: 42.92. I tana huihuinga whakamutunga, te 4 × 100 mita medley relay, i wikitoria a Vollmer i tetahi atu koura me Missy Franklin, Rebecca Soni me Allison Schmitt. I te kaukau i te waewae parirau, i tuhia e Vollmer he wa wehewehe mo te 55.48, i te wa i whakaturia ai e te roopu US he rekoata hou o te ao me te waa o te 3:52.05, i pai ake ai te rekoata o mua o te 3:52.19 i whakatauhia e Haina i te tau 2009.