First: Congratulations on putting together your exit plan and getting out when you needed to.

Second: Recognize that there is something broken in your family's culture where they think they are owed your time and labor. Your sister's the one who chose to carry a pregnancy to term. Your parents are her parents and she is their responsibility, not yours.

Third: Set and reinforce firm boundaries with these people. Yes, you love them. You can love them from a distance. You don't owe them time, money or effort. They should have plenty in reserve after using you for free household labor for a decade. Now is your time to sink your energy into your own future. NTA.