Mental harassment by Mother in Law

I am married for 11yrs now and I have a 9yr old son. We bought a house 2 years back where my Mother in Law gave the down payment of Rs 70lakh and I took a house loan of Rs 90lakh. Since then I have been paying the EMI until today and have been running the house without any expectation from anyone to have a good environment in the house. My salary is approximately 1lakh in hand however the house expenses are about 1.7lakh every month including EMI/ school fees/ house maintenance/and all sorts of additional expenses. My husband has a very minimal salary and his job is very unstable. My mother in law keeps putting unnecessary allegations on me without any reason and keeps spoiling the environment of the house. because of this My son is also suffering as I have to leave for office in the morning and he has to face her hatred for the entire day in my absence. He is unable to concentrate on his classes also since the classes are also online now.She wants to sell of the house and take her money and leave. I am ok to do that but my only thing will be she will not interfere in my life or my sons life again. How can I make sure about this.