Illegal Claim on our property

We have an ancestral and joint property in the heart of Guwahati, Assam. It is co- owned by my mother in law (Padma Devi) and her sister in law (Maya Devi). Though the property is co - owned we have separate houses and both families are well aware that if ever the property is divided then the area which is occupied by both the parties will never be disturb. Due to sudden deaths of our fathers in law, both the co - owners did not thought of dividing the property and now all the sons and daughters are not filing for the same as no one is disturbing the other in any ways. Maya devi's youngest son (Mr. Deba) was given a portion of room within our house (Padma Devi's)to do his business as he was unemployed . We allowed him to do business as the room was vacant as well. this man passed away in Oct 2014 within a year of marriage.Now the widow (wife of Deba) claims that either she be paid allowance of Rs. 30000/- or give the same room to continue her business. An FIR has been lodged. * Mr. Deba had never paid a single rupee for the room that we have given him for doing his business. It was entirely out of love and his pitiable condition that we offer him the room. No document was done regarding this. * His wife did had a beauty parlour in the near neighbourhood but a month after her husband passed away , she closed her parlour. My Question is Can this widow claims the house as hers because it was given for doing business to her husband? She did not ask any other rooms that is vacant in her own in law house (Maya Devi's area) and is claiming my room. What are the options available for me?