Am I demanding too much of my mother-in-law?

After giving birth, I reduced my workload to take care of my child, so my income dropped by half to VND10 million ($423). My husband's monthly salary is also $423. We contribute VND4 million ($169) to general household expenses together, mostly via bills every month. But this amount seems not to be sufficient in the big city. My brother and sister-in-law work in another city, they have high incomes but don’t help out our household.

My father-in-law receives a pension but doesn't share it with my mother-in-law. He also keeps any income they make off their rentals. My mother-in-law is 70 years old but still in good health, and she stays physically and socially active. My father-in-law is weak, though, and so he lets his wife handle everything for many years. I hope that she can take care of my baby for another one or two years because I need to study further to raise my income.

She gives time for her grandchild but prioritizes other things more than taking care of my child, such as going out with friends. We expect her to stay home for another one or two more years, then we will send our baby to daycare. But she and I have started to argue a lot about this. She said that we were demanding too much and being disrespectful.

Recently, she was so angry that she ignored her grandchild and I was upset about that so I ignored her. My mother advised me to remain patient because my mother-in-law is quite kind, caring and communicative. It's always us that start an argument with her. For example, we asked her why she went goes out too much and why she does so many nonsense things. She's never started an argument with us.

Since giving birth, she has helped me with laundry and cooking. After she got angry, I think maybe I've demanded her too much. I intend to contribute more to our household expenses and have decided not to interfere with her personal stuff. I want to have a happy atmosphere at home for my child.

Have I demanded too much of my mother-in-law? Is it wrong that I'm often grumpy with her?

Should I change anything to avoid conflicts in the future? Or should we find another place to stay?