Why would a mom be thoughtless towards her adult children?

My mother is something else.
I come home from work 11:30 pm after being sick for three days now. I was allowed to work without interacting with anyone. And she waits up for me to flat iron her hair. I told her I am sick. She is insisted. And begins to criticize my weight and ask me if I went to the gym. I told her I am sick and could not go to the gym. She has known this. The strange thing is, she asked me how I felt when I walked in the door. I told her I was still sick and she got concerned that I wouldnt be able to do her hair. Now she’s upset. I just went to bed after she asked my to had her the flat iron. What makes my mom act this way all the time, and expecting me to cook all the time? She is not helpless.