How do Jeannette's parents react to her decision to leave Welch?

tries to entice her to stay, promising to resume work on the Glass Castle but Jeannette tells him not to bother building it for her sake; she is leaving Welch even if she has to walk to New York City. Rex walks his daughter to the bus station to see her off and he gives her his favorite jackknife for protection. From the bus, Jeannette turns around to wave goodbye to her father and wonders if she will indeed make it in the big city.

Rose Mary was upset when she learned about Jeannette's plans to go to New York, but not because her daughter was leaving.... she was upset because she wasn't.

"Fine. Go."
"What's wrong?"
"Nothing. You should go. It's a good plan." She seemed on the verge of tears.
"Don't be sad, Mom. I'll write."
"I'm not upset because I'll miss you," Mom said. "I'm upset because you get to go to New York and I'm stuck here. It's not fair."