Does my sibling have any obligation in helping with taking care of our senior mother?

My Father passed away in 2016. At that time both me and my sister were living in the US. I moved back to India in 2017 and after a few months took responsibility of taking care of my Mother. My Mother moved to live with me in the beginning of 2019. Since then I have been her 24x7x365 caregiver. My sibling does not help at all with any form of caregiving. She hasn't even visited India since Dec 2018. We also do not have any relatives/friends to help with the caregiving. I do random freelance work from home since I cannot work in office or travel for work. I have not taken any vacation/break since 2019. I cannot stay away from home for any extended period. If I go anywhere I make sure I'm back within 3-4 hours because my Mother is at home alone. She is also very 'dependent' and does not do any cooking, shopping, money management, visiting doctors on her own etc. So I have to take care of everything. My question is: Does my sister have any obligation in helping with taking care of her Mother? After all, she is not just my Mother, she is also her Mother. I do not have husband/kids while my sister has a husband and grown up kids. So it is 'assumed' that I should be serving since I do not have a life.