This is what we found on Wikipedia regarding the Billie Marten:

Isabella Sophie Tweddle (born 27 May 1999), better known under the stage name Billie Marten, is a British singer-songwriter and musician from Ripon in North Yorkshire. Her stage name came from her family's desire to keep her real name private because her music career started when she was a tween. She first came to prominence at the age of twelve when a video on YouTube of her singing garnered thousands of views. She released her first EP at the age of fifteen in 2014, and her second EP a year later. At the end of 2015, she was nominated for BBC's Sound of 2016 award. She has since released four full-length albums: Writing of Blues and Yellows, Feeding Seahorses by Hand, Flora Fauna, and Drop Cherries, all of which have received critical acclaim. Her style can be described as singer-songwriter and folk.