3 years ago, after a horrifying day, my toddler was diagnosed with a huge brain tumour. It was mostly removed the next day in very risky surgery.
It was 50-50 whether it was going to be a type that would kill her (100% mortality rate) or probably wouldn't (10% mortality rate).
That night, I held him and silently sobbed all night. My first prayer was that it was the 'better' type, but my second was that if it was the terminal type, that he'd die on the operating table and so would never suffer.
I also had the realisation at the time, that as much as I'd have been willing to do what that lady did, if there was no other way for him to escape suffering (and then join him), a younger sibling meant I couldn't.
The coin fell in his favour, and I started this post with him tucked up against me asleep, and the future looking ok. Bullet dodged but the darkness of that night will never leave me.
I don't think anyone who either walks or gets a glimpse down that road, especially for a child will feel anything but sadness and understanding at the decision this woman made.