MIL forcing me to wash husband's underwear

am horrified... Is washing husband's underwear my duty? i am a working woman who earns her bread butter and supports husband financially...I am a staunch believer that if i can do chores that men can then even my husband can do some household chores independently.. ..Anyway Husband never will support the fact that i do all the things my traditional MIL tells me to do.. .however in his absence, she tells me to wash his underwear. I feel so pathetic..Does she tell him to wash my underwear? I ofcourse told her no i wont.. Even if she is an overly concerned mother i dont think this is justified

Note: obvio there is a washing machine, she asks me to HAND WASH IT

Update: spoke to husband about it. He assured me that he is responsible for his tasks and in no way should i entertain whatever crap she says. Also, he checked upon me , if am ok..I don't even wish to talk to her henceforth.