The point is not to insist that we know better than the Lord about what we should have, to demand, to try to bend God to our will rather than conforming ourselves to His will. We are to pray as Jesus did in the Garden of Gethsemane: He prayed "Let this cup be taken from Me," but also, "Nevertheless, not as I will, but as Thou Wilt."
But we do know God’s Will when it comes to healing. What did Jesus do? He healed everyone that He encountered. No where did He say - this one isn’t My Father’s will to heal.
Excellent post! Pray for relief and comfort, but above all pray for acceptance of God’s will.