Ka cika wannan magana: Marshall ya wakilci Amirka a Wasannin Olympics na shekara ta 2008 a birnin Beijing, a ƙasar Sin. Ta sami lambar tagulla ta hanyar yin iyo don ƙungiyar Amurka ta uku a cikin zafin jiki na farko na
'yan mata 4×200 mita 'yancin-style relay. Ita da 'yan wasanta na farko sun kafa sabon tarihin Amurka a cikin taron.