Crowdsourcing answers to an important question from a child

A reader whose name I want to withhold (for obvious reasons) asked me this question. I answered the person, but I also asked if I could put the question up, as one might get better advice from a panoply of answers from readers. The parent said "sure". So if you have time, please give your answer, and I'll alert this concerned parent.

Lo, the question (main one in bold below):

I'm long time reader of your website, and this is my first email to you. First let me say that I greatly enjoy your content, especially the science posts!

I've been motivated to write this email because of a question my 7-year-old daughter recently asked me. She loves to read, particularly about nature, and is a lover of big cats (especially cheetahs!)

Also, like many children her age, my daughter believes in God. She clearly sees God in a functional role as a designer. When I asked her if she could imagine a Universe without God, she answered, "but then how did everything get made?"

Neither my wife and I are religious, and we are not forcing her into atheism. Rather, we help her think through her questions and arrive at her own answers. Recently, one her questions provided us with a very good learning opportunity.

After learning more and more about a cheetah makes her living, and the tough life of a predators (and prey) in general, she was very upset. She asked me the following question:

"Dad, why did God make life such a challenge?"

When I asked her what she meant by this, she elaborated. She knew that cheetahs have to work very hard to get their prey. She knew that if the mother cheetah couldn't catch enough food, her cubs might die. She knew that the cheetah's prey must constantly be on the watch in order to survive. She knows about droughts and floods, and parasites and sickness, and that most baby animals don't survive. Why, she asked, did God make it so tough?

If I was still a religious person, I might have given some vapid answer about God's mysterious ways, or perhaps a horrid explanation about how the sin of Adam is responsible for all of this! But as a reasonably informed layperson, I think I know the answer to my daughter's question, and it has a lot more to do with Darwin than God.

So Jerry, can I ask you a favor? Do you think that you can provide, in a concise form that is understandable to a 7-year-old, science's answer to why life is such a challenge? I would greatly appreciate this opportunity to give my daughter a far better answer to this question than what a child typically gets.