My situation is a bit different. Its my daughter saying it about ME!
I just tell her that it sucks at times, but we all have things that we dont like or have to do (Daddy has to work, she has homework, I have my treatments etc)
If you make it seem just like one of those things in life that we face & dont have a choice then maybe it will ease her mind a bit. She will still be annoyed, but eased!
Good Luck