I don't believe that it's G-d's will for people to commit sins. However G-d can turn those sins around for a good purpose after the fact. For example, it's evil and horrible that so many black mothers abort their babies. G-d can't want an innocent baby to die like that, to be murdered in cold blood. The mother, the abortion doctor, and all others who are responsible for this sin will be called to account for it on judgment day. However the crime rate does go down somewhat, and it may save someone else from being murdered, raped, robbed, etc. later, but I don't know if that's really a silver lining when you consider a horrible crime has already been committed.
Can't remember her name right now, but that lady who survived an abortion and does speeches now would never have had that kind of career speaking out for the rights of babies to live if she hadn't gone through what she went through. She may have grown up pro abortion even. It was evil and horrible what happened to her and it was in no way justified. However maybe she saved more baby's lives.
I still don't think we should pray for people to sin, even if God can make the best of a bad situation.