is it okay for me to be quiet?

Hi everyone! I'm a preschool teacher. I am 6 months pregnant. When I came in for a Saturday duty, i was asked to wash three types of toys in all classes. From pg to K2. As well as wipe all the tables. My boss kept indicating to do it slow and I'm not the type that says no when she talks. But as I was doing class by class, my legs were all aching. I mean as a woman she should know right ? I'm so confused. Should I tell her off? Please help. Thanks 🙏🏾😬