Hissey came to Sikkim Himalayan Academy when she was six. She lived at the school, as did most of the children, because her home was too far away to travel, and in any case her parents would not have been able to afford the transport. She could not attend the closest state school to her home because daily travel would also have been impossible and there was no state provision for living away from home.

At school she was always quiet, with a small group of close friends.

She took her studies seriously, and had excellent results.

Hissey had been picked out to attend Dr Graham’s Homes school in Kalimpong because of her good results. She was lucky to go to Dr Graham’s at an early age, but it must have been difficult for her, as there was a group of four boys from SHA at the school, but she was the first girl.

Later other girls from SHA joined her, but they were older.

Her reports were very steady, she kept up with work and participated well in school life, achieving good results in here year 12 public exam.

In July 2017 Hissey started started her BA in Political Science and Journalism  at Mount Carmel College (MCC) in Bengaluru (Bangalore). Mount Carmel College is an autonomous body governed by Carmelite sisters of St. Teresa (CSST). Affiliated to Bangalore University, MCC is ranked among the top twenty colleges in India.

In 2019 she did an internship at the Summit Times, an English language newspaper based in Gangtok, the capital of Sikkim.

She graduated with First Class Honours in March 2020. Her further education was then very much disrupted by the Covid pandemic, but in October 2021 she gained a place at Sikkim University to study for a Masters Degree in International Relations.