Complex sentence: Del Rey won the award for "Best Alternative" at the MTV EMA 2015, she previously won it in 2012, making her the only female artist to have won this award, and winning it twice.
Split into simpler sentences: Del Rey won the award for "Best Alternative" at the MTV EMA 2015. She also had previously won it in 2012, making her the only female artist to have won this award, winning it twice.