Praying When You Don't Know What To Ask For

I have a dear friend who is dealing with breast cancer and chemo.  That is enough to test your faith and endurance.  But, even before the diagnosis of her cancer, her 8 year old little boy was diagnosed with brain cancer.  He had surgery, radiation and chemo.  After a long stretch of trips to Dallas Children Hospital he was pronounce "cancer free".  We gave him a huge "No Mo' Chemo Partaaaaaaayyyy".  Then at a routine MRI a new tumor was found.  He under went another surgery.  This time the tumor was too large for them to get it all.  He went back later for a gamma knife procedure which went well.  He was put in case study that DCH was working on.  His mom gave him the chemo by mouth every day.  He went back for an MRI.  The results were devastating.  The MRI showed 3 new tumors.  The chemo is not working and the doctors told her to stop giving it to him.  They told her they didn't know what more they could do for him.  But, they put in a call to St. Jude's.
St. Jude's as a study they are doing.  They have no documents or anything to go by.  They can't tell the family what the drug might do to him good or bad.  The family had earlier decided to try some "Natural Remedies".  Now, they are back to second guessing what they should do.  People can say "Well, if it was me or my kid, I would. . ."  But, bottom line is NO YOU DON'T KNOW!  Until it is your child, you can't answer that question!  And I pray you never have to answer that question.
We had special prayer for them at church this morning.  What can you pray in a situation like this?  I pray for peace in their hearts what ever decision they make.  I know they are seeking God's guidance in this and I pray they will let people who love them support them whatever decision they make.
This morning was the first time I witnessed the little boy actually break down and sob.  I grabbed him and held him tight.  I didn't want to let go and I am not related to him other than through Jesus' shed blood.  I have told his mom to call me 1 or 1 meaning AM or PM.  Until today I had never said that to him.  I hope they know I mean it.