The post that was quoted here has been removedAs a possible (though not exact) analogy, should a Jehovah's Witness *child* have the right to refuse a blood transfusion after being informed that it's needed to save one's life?
This has been tested in court. It depends whether or not the minor can demonstrate to the court that they have a valid grasp of the principles and fully understand the consequences of their actions.
The Jain case is a poor comparison for while I note that you correctly state its not an exact analogy its in my opinion so far removed that no logical comparison can be drawn because it was the direct consequence of the adherents will, not a reaction to a situation over which the minor has no jurisdiction as in the case of haemophilia or some other life threatening ailment which would normally warrant an intravenouses blood transfusion.