Sovereignty

The Sovereignty of God is a tough thing for me, and I think most people, to understand.   Lets start with a quote from Piper's Desiring God, which I'll add I agree with.  

". . . the suffering of sickness and the suffering of persecution also have this in common:  They are both intended by Satan for the destruction of our faith and goverened by God for the purifying of our faith . . . Satan is not the only designer in this affair.  God rules over Satan and gives him no more leash than can accomplish His ultimate purposes.  Those purposes are the opposite of Satan's, even in the very same experience of suffering."

He goes on to quote Paul, how we are above all other people to be pitied most if there is no resurrection.  This is because the suffering to which we are called by and in Christ has no honor or value outside of the hope of joyful resurrection.

So, back to sovereignty, this all gets tough when we take it out of the context of textbook head knowledge, and look at real lives going through real suffering and real sickness.  For example, a lady my dad works with has a 10 year old daughter, chyenne, who a couple years back was diagnosed with both types of leukemia.  I didn't even know there were two types, and apparently it's unbelievably rare amongst people with leukemia to have both.  Anyways, she has been through two bone marrow transplants, etc. etc., and just recently found out that it's back again.  Since she has had two transplants already, she is not a candidate for a third, which basically gives her a matter of months to live at most.  

Now I know, she isn't in reality an "innocent" little girl, we all are sinners, but still.  How and where is God working to His glory in this girl's struggle and impending death?  What plan of God's do I tell her mother as she prepares to tell her daughter about dying?

I have some thoughts on answers, but would love to hear what everyone else thinks.  I think these types of questions are of paramount importance as we seek to delve deeper in understanding of God and the Gospel.  Not only is it of little use to know a bunch of things that have no impact on your life (see pharisees), but I would challenge how much is truly understood if it doesn't have an impact (again, pharisees).  Let the thoughts flow!