We had a sudden very serious diagnosis for our then toddler. It was 50-50 whether she'd have a variant that was effectively terminal on diagnosis, or one where she'd be very likely ok (which is thankfully the one she had).
She had emergency surgery and I prayed that if it was the nasty one, that she'd die in surgery, rather than recover, have months of treatment and then inevitably die a distressing death.
This was me praying that the daughter I loved with all my heart would for in surgery if terminal. She's lying beside me in bed now, and for that I'm so grateful.
I know of others with the nasty variant and how futile treatment is for it, and the horror of the end. I am not horrified by the idea of tightly controlled toddler euthanasia where the alternative is intolerable suffering with an inevitable death. It's what I would have wanted for my child and would have been a mercy.