I think too that you did a good job with Blythe. She is clearly a way more complex character than we had initially been led to believe, but the show never had a chance to explore that further. I do think she loves her son, but she obviously spun a web of lies at one point early in her marriage that she could not get out from under, and its consequences continue to play out through season 8. I wonder if that is where Greg first developed his motto of "everybody lies"?

I also think by this time she realizes it is too late to help Greg, and seeing that she failed him when he was so young, she feels that respecting his wishes now at least makes sense.