Mimmi is the younger sister of singer Molly Sandén who represented Sweden in the Junior Eurovision Song Contest 2006 and Frida Sandén who represented Sweden in the Junior Eurovision Song Contest 2007. Mimmi become the third Sandén sister to represent Sweden in the contest, where she performed the song "Du" in the Junior Eurovision Song Contest 2009 in Kiev. This was not be the first time Mimmi stood on stage in the Junior Eurovision Song Contest as she was in the choir behind her sister Molly along with other sister Frida Sandén during her performance in the Junior Eurovision Song Contest 2006. Molly then as a favour was in the choir during the Talang 2007 final when Mimmi performed.