I'm going to go against the grain here.

If my child ever said anything like that to me I'd put it back on them and ask them "What does that mean?" See if they really understand. If they don't it gives you the opportunity to discuss it with them. If they do, ask them if it's been said to them before and ask them how it feels? And also acknowledge their frustration, give them alternatives. For example if they are grumpy because they don't get what they want they can express that. Sometimes its just about being heard. If you were to say "I know you are upset but the reason is xyz." 2 things will happen, they'll understand why and realise it's not a personal attack, and lets face it most kids think it's all about them and if that doesn't work they'll get sick of your voice

She doesn't mean it, and I know you know that but that doesn't mean it doesn't hurt.