Natural consequences are good too. I ate so much candy at one Halloween that I was so sick for two days. And I never did that again. Mom and dad just sat back and observed. You know it is important to pick your battles, so see if you can let go of the worry and be part of their enjoyment of Halloween, rather than leaving them with a sour picture of you trying to control them at this fun time of year.
Childhood memories are very powerful.
Think back on your childhood as to what you remember as good and bad and how what your parents were telling you at these times. She could feel that she has an unfair amount to do. Listen with a very open mind and know that the reasons for her hesitations are very real to her. Maybe you could have a family meeting. Write down all the chores that need to be accomplished on index cards, and have the children and adults pick the chores that they like doing the most.