In chapter 7, what worries Levy about Ender?

As with the other chapters in this book, chapter 7 starts out with a conversation between two adults. Readers know that one of the men is Graff, and chapter 7 reveals that the other man is General Levy. His overall main concern about Ender is that Ender is just a kid.

But shouldn't they still act like children? They aren't normal. They act like—history. Napoleon and Wellington. Caesar and Brutus.

It concerns him that these young children do not act like children and that they are not treated like children. He fully understands why this is happening, but it does weigh on him. He knows that there exist physiological things that simply cannot be sped up, and he worries that kids like Ender are not given enough time to mentally and physically recover from test to test.

So as soon as he can cope with a situation, you move him to one he can't cope with. Doesn't he get any rest?

The conversation ends with Levy expressing concern over Ender getting hurt. He warns Graff to not hurt Ender, and Graff is shocked by this statement. Graff knows that in order for Ender to become who and what they need, pain is necessary. Levy clarifies by telling Graff to not hurt Ender too much.

"General Levy has no pity for anyone. All the videos say so. But don't hurt this boy."
"Are you joking?"
"I mean, don't hurt him more than you have to."