Am I a bad person?

My coworker is about 3 months pregnant. She’s been scheduling herself to work full time, but then calls me in or makes me stay way later (13 hour shifts), while she just sits there. She keeps on saying she has morning sickness which I understand, but if you can’t work then please don’t schedule yourself hours you know you can’t work. I’m tired of pulling all of the weight, I really just want to quit since I’m practically running this place all by myself, while she soaks up hours that could be used on someone else able to work.