When state representative Jeff Hayden was elected to the Minnesota Senate in October 2011, he vacated his seat in the House of Representatives. Allen was one of four DFLers to put themselves forward for the seat and, at the DFL nominating convention held on November 12, she received the party's endorsement on the third ballot.[6] She nevertheless faced a primary election on December 6, facing three opponents, two of whom had suspended their campaigns after losing at the convention. Allen won the nomination handily, taking over 82% of the vote in the primary.[7] In the general election held on January 10, 2012, she faced only one opponent, who ran under the "Respect" label, beating him 56–43%.[8]
She was re-elected in the 2012, 2014 and 2016 general elections. She did not seek re-election in 2018.
