Trouble forgiving my mil

Yesterday I visited my mil. She fried some French fries. I told her my son is having cough and she argues back that she used clean oil to fry... fried is fried. Some more she has her kids and other grandchildren to eat. But she was insistent my son eats it. And in order to show she has overriden me, ask my son is it nice??? Then when my sis in law was in the living room, my mil suddenly changed. She was holding a box of blueberry and she pretended to be scared of me and ask if my boy can eat the blueberry... if the French fries she already overriden me, what's the point of asking me on blue berries. I am really sick of this double faced and then cause I show my black face... now i am the villain... I really hate dealing with this situation. Its been 3years since my boy is born and I need to deal with her everytime I see her.... I really don't know what I can do. Should I text her or reprimand her in front of the famoly#firsttimemom #firstmom #newmom