You have to move around after surgery. Staying in bed is the worst thing you can do.If you are supposed to stay in bed to rest what I am assuming is an incision then I would say, I cannot get up, you feed it/them please.
If you are recovering why is she asking you to do physical tasks?
Everyone is responding as if there is some long history and other posts you've made and they all seem familiar with your backstory. I am not.
If I am recovering from surgery I just say, I need to stay in bed you feed them. I'd probably say "you know I am recovering and need to stay in bed why are you even asking me to get up?"