polygone said:
Please feel free to discuss what an Atheist would say in such a situation

.
Depending on what the situation was... I'd attempt to offer an appropriate response.
From an atheist view, in general, why do people suffer?
It's a necessity. If there is something good, there must be something less good, else it wouldn't be good--it'd be the standard. So the less good is then the suffering.
Because I would want to keep a dying 7 year old happy, I'd try to console her. Lie to her, say "it's all going to be alright". If she insisted on knowing *why* this was happening to her, I'd explain that it's so she can reflect on the good times she's had, and appreciate them more. Do I believe this is the reason the illness affected her? Of course not.
What does she WANT to hear? There is
no good answer (from any religion, or lackthereof)--she's suffering because of an illness--diseases aren't
earned ... of course there's a scientific reason: I know absolutely *nothing* about Leukemia... it's a specific type of cancer? I'm not qualified to scientifically explain why she's suffering. I wouldn't give her that answer even if I was. People suffer for various reasons. In the 7 year olds' case, it's whatever caused her Leukemia.
(What kind of answer is that though? What caused her suffering? Her Leukemia. What caused that? I don't know. Some scientists who study it probably do.) But it all bottoms down to an unfair, unjustified illness.
Life's a pain and then you die... it's just a bigger pain to certain people. Get over it. Somebody's always got it worse than you do. You've got to make the most of what you have--she really didn't have much, if she's dying that young, but...
Best response I can give.
Edit: Oh, and the Christian response would leave her happier than the Hindu response because it's assuring her that she's in God's hands. That it's all part of a master plan, that it's gonna work out. The Hindu response is saying it's her fault--not something that's going to make her happy.