When I read the thread title, I thought you had teenage kids ..
She´s 5 and doesn´t understand what she said. Talk to her about it. What would happen if you weren't around. Consequences of this. Tell her you understand that she doesn´t like school. One of the best parenting advices I´ve ever got was to declare to your kid that you understand what they are going through. Not only "it´s not allowed" or "because I say so", but rather "I understand that this upsets you and I can see why. Let me explain to you why I´m doing this." Same goes for the typical "Don´t you want to clean up your room?"-question. It implies that you are giving your kid a choice, but in the end its a demand. Kids learn this way that their voices don´t matter. "Please clean up your room. Shall we do it together?" works so much better.