She graduated from Elva Music School where she played violin and has studied at the Elva Song Studio and Ülenurme Music School under Ursel Oja.

Her musical career began as part of the group Ekvivalent, but her breakthrough came thanks to a competition run by the Estonian radio station Skyplus, in which Mari-Leen reached the final.

Mari-Leen started her solo career with a cover of the Finnish hit Levoton Tuhkimo by Dingo, titled "Rahutu Tuhkatriinu'".

After the first single made it to the first place of the Estonian charts, Mari-Leen again topped the Estonian charts with her first solo-album Rahutu Tuhkatriinu, produced and written by Sven Lõhmus, in December 2006.

In December 2011 Mari-Leen stated tiredness of her singing career and therefore decided to give it a pause.