If you cave in when they are little it will not be easier when they are big. Maybe, but you are also a parent. You are setting standards of behavior. If you let your kids kick over boundaries at home you are teaching them how to misbehave in society. Not a good idea.
Society wants commitments kept, assignments done and laws obeyed, employees who are responsible.
When our kids do not respect Society's boundaries they are at risk for heartrending consequences. Mercifully, she is not present. Now I, who do not love her at all, will sentence her to three years in juvenile hall. She will be on probation for another three, after that.