Will the questioner be considered sinful and disobedient to her parents if she leaves her job to care for her daughter, knowing that she spends on her poor parents and that her married sisters do not contribute to the expenses nor wish to work?

There is no sin upon you for leaving the job, as a woman is not obligated to work to support herself or others. Her financial support is obligatory upon others if she is poor, whether she is married or not. Leaving the job is not considered an act of disobedience.