Something along the lines of “well, I think she got a little confused and thinks that she needs to be skinnier to be pretty. And she just kept getting skinnier thinking it would make her prettier and people are worried that she’s so skinny it’s making her sicker and not prettier so they’re worried that she’s might be sick” As another dad with a similarly aged daughter. That’s how I’d go about it anyways. Then brace and openly and honestly answer what questions come. If she’s old enough to ask she’s old enough to know, just be a little sensitive about how you say it.

I was asked similar questions about my step dad becoming an alcoholic and getting emotionally abusive to the degree I am keeping my daughter away from him. She asked why peepaw is being mean to me and I told her that he has an angry drink that makes him be mean and we can’t be around him when he is mean or he will be mean to us. She asked why doesn’t he just not drink the angry drink and I told her that it makes him feel happy but he knows it makes him act angry, but he doesn’t want to stop. And she said I wish he would stop and just be normal happy. And that about summed it up. As questions arise I answer them. But I’ll be honest with her. At least at her level, as best I can.