Most of the NGO events are held in the Church Center across the street from the UN, and are as far as I can tell open to the public.
I went to one event held by Penal Reform International. They spoke of the atrocious societal problems that arise from having so many women encarcerated around the world. Some truly horrible stories here.
The speakers argued the main challenge was to change policies that land so many women in prison, and secondly to improve conditions in prisons, plus access to counseling after they are released. Spanish prisons were held up as an example. Women can have their children with them in the cells (and prison nurseries) until they turn three.