My sister-in-law doesn’t contribute to household expenses despite living with us

I am 30 years old, living with my husband and his sister in Hanoi. We have not yet had children. The money, given by my husband, covers our groceries and utilities, while he pays the rent separately. This amount is barely sufficient for three people here, particularly when food prices spike following typhoon Yagi.

Recently, my sister-in-law requested that I purchase breakfast for her. I declined, citing a lack of funds, which she perceived as stinginess and complained to my husband. This led to a confrontation when my husband returned home. I explained the high living costs and our tight budget, stating that if she does not start contributing, I cannot afford her breakfast.

Following our discussion, communication has broken down between my husband and me. My sister-in-law has also openly shown her displeasure, ignoring me upon returning from work and frequently dining out instead.

Two years ago, I was diagnosed with a non-terminal, treatable illness, but it has left me with weak health. I often experience dizziness and have fainted several times. After a serious fainting incident resulting in a broken arm and facial bruises, my doctor advised me to stay home. This situation has been exasperating, particularly as I navigate the perception of being financially dependent on my husband while also dealing with my inconsiderate sister-in-law.

My husband and I have faced challenges in having children. Whenever I bring up fertility treatments, he expresses concerns about my health. He prefers waiting until my health improves, my job stabilizes, and we have additional income. Meanwhile, he allows his sister to depend on us financially.

How can I shift his perspective and encourage my sister-in-law to contribute financially to our household expenses?