
Because it’s pointless. She already sensed that his powers would grow in a way that surpassed the one she had in the last. She knows his personality and she knows the magic will return to the forest once they leave. It’s the magic there that keeps the dimensions intact. I’m guessing she’s playing a long game of going now and figuring things out later.

She can’t use her magic… that’s why she had the trees there to work for her… and she could already tell he would surpass her in terms of power when he was a kid. We’re at that point now. And it’s not like she hates him. Just going with him was the best decision as the forest would began to heal itself once they finally left.
She just a went with him??? No argument?? After all that time trying to protect the forest??