NGO terminated employment without pay

Hello , My sister was employed by an NGO in almora. She worked for a month, they in writing communicated to her that during the months of Dec to Feb and monsoons she need not be based out almora and can work from Delhi. On 16th Feb , after spending 2 weeks in the interiors of Almora , she returned to Delhi. She was working from home , doi g back end work of designing documents. She was supposed to be in Almora on 1st of March. However she fell I'll due to weather and wasn't in a condition to travel. She was still trying to workout a way to make it to Almora. On 27th Feb the trustee of NGO called her and she shouted at her. Next day she sent her a termination letter. They didn't pay her the salary of 1 month , plus as per the contract 60 days notice period or 60 days salary should be paid in case either party terminated the contract. We have approached labour court in Almora, labour commissioner sent a notice to the NGO but now NGO claims that my sister can't file a complaint in labour court as she doesn't come under 'workman' Can someone please advice us how to go about it? It will be of great help if someone can guide us Looking forward Shashank