Hmm, with this new info, I'm going to have to reconsider and move over to the mother's side.
Even if she should have been the one to decide in the first place, who in their right mind would go through this sort of fight after the remains are in the ground?
She is obviously just wanting to piss off the dad.
I was squarely on the fence until I read this sentence:
Initially there was consensus among all family members including the mother that Oklahoma would be the final resting place for Jason, but the mother unilaterally reversed this decision.Had she been so certain that his desire was to buried in CA as she is now, she couldn't have been part of a consensus that he be buried in OK and later change her mind.