She works with Thai Lawyers for Human Rights (TLHR) and is one of the legal representatives of the fourteen student activists from the New Democracy Movement (NDM).

She has been the subject of harassment and threats from Thai authorities, as well as criminal charges related to her work as a human rights lawyer.

[2][3] In 2015, Charonsiri obtained the release of photojournalist Anthony Kwan Hok-chun, of the Initium Media organization from Hong Kong.

Kwan, who had come to Thailand to report on the bombing of the Erawan Shrine, brought protective gear including a flak jacket and helmet, unaware that the items were controlled under Thai weapon's laws.

[9][10] After attending the 33rd general United Nations Human Rights Council meeting in Geneva, Charoensiri was issued a summons for additional charges of co-conspiracy and sedition.