Iam truly sad for what you went thru at such an early age..And your parents gave that poor child the most comfort they couldI have told the story before, and had some fundies castigate my parents for not doing everything possible to prolong her life for every moment they could.
In cass of terminal illness I think you will find most Christians are on the side of comfort and care until the inevitabld happens. We belueve God says do not kill..there was no mention of keeping a person aljve indefinitely on a rezpirator..back a few decades I did Eegs. It was this test which determined whether or not a person was brain dead. I swear in one case I personally felt the methods for life support beyond what was useful were keepjng the the mans spirit from moving on to tgd next life. Many Chtistians have advance dire tives..so please dont feel we all think the way you described. I would neved hasten the end of a life..i would not prolong pain. And I do nog believe in artificial measures where it is not called for.
Now in the case I mentioned before with a botched abortion the admjnistrator took it on herself to snatch up thd ALIVE baby and trash it..dsspite the mom deciding she wanted it..This is neither a caring or medical solution..the doctor was nowhere to be found..
Anyway sorry for your loss and any insensitivity about it