I think OP and all the posters on here moaning about MIL always assuming that cooking food, getting up to children in the night and doing housework is woman's work, should think about what MIL's life was like and cut her some slack.
I'm of the MIL generation, in fact I'm probably quite a bit older than most posters MIL and I can tell you that in their days all these things would have been their jobs. Whether they had jobs outside the home or not, they still did all the 'wife work'.
I doubt, in the case of most of them, they're saying these things to put you down or in a passive aggressive way, they're just making the assumption that your work/life balance is the same as theirs was; and from what I can gather from one of my daughters, for a lot of women it's still the same.
My exh did absolutely nothing in the home, nothing with the children and the idea of him attempting to cook even the most basic meal is laughable.
He also continued to pursue all his hobbies after we were married, which meant I was on my own most evenings and every weekend; all these things contributed to him being my exh.
I don't make the assumption that my daughters/daughter in law should be the ones doing the wife work because that's not how my mind works; also I grew up seeing my own father cook and involve himself with us children so my perspective is probably different from a lot of your MIL.
In so many ways things have moved on for women in regard to outside working and in the home, but remember whilst you and your DH/DP might split house work, cooking and childcare equally this would very likely not have been the case in your MIL's day and for many, many women it still isn't the case.