There's nothing "kind" about seating an 8 year old with an adult caregiver. It's mandated by the WestJet policy quoted in the post after yours, and also mandated by Canadian regulations (at least that the child and caregiver must be seated in the same row, separated by no more than one seat or the aisle for a child between 5 and 11), and this must be free of charge. It's also the minimum for basic humanity, not to mention all the other passengers on the plane. I sure as heck don't want to be seated next to a child who couldn't be seated with their parent!