Cheyenne Rose Antoine, 21, pleaded guilty on Monday to killing Brittney Gargol, 18, in Canada two years ago.
Ms Gargol was found strangled to death near a landfill in Saskatoon, Saskatchewan with Antoine's belt near her body.
Antoine was sentenced to seven years for manslaughter.
She was identified as a suspect after she posted a selfie on Facebook of the two of them, showing her wearing the belt hours before Ms Gargol died.
