[2] Mathews was born in Rotorua, New Zealand, and began ballet lessons with her sister in Tauranga at the age of 5.
[3][4] When she was 15, she was accepted into the Royal Ballet School in London, and studied there for three years.
In 2008 she joined the Birmingham Royal Ballet and became a principal dancer in 2017.
[2] In 2020, she left the company in order to return to New Zealand and raise her first child.
[5] Delia and her husband, a British civil engineer, now run an off-grid hotel retreat they built near Tauranga.