Guess Who This Pigtail Princess Turned Into!

Before this smiling girl with curls would grow up to become a platinum-selling singer, she was just a Jersey kid struggling to fit in.

Her stage name is an anagram of her real first name, and also the name of a street in Brooklyn she spent time on in her teens ... as she was beginning to write music.

Her rise to fame began by posting videos on YouTube and Tumblr, and she became known for a parody of a Taylor Swift track. In 2014, she released her debut single on SoundCloud and it became massively popular ... leading to her signing a record deal.

Soon enough, this young lady began touring with the likes of The Kooks and Imagine Dragons ... and that SoundCloud track would become her first single on her debut album.

Five years, another certified platinum album and several chart-topping hits later -- including one with The Chainsmokers -- this pigtail princess is one of the hottest acts around ... and her third album release is just days away.