She could go to a totally different industry, but she'd be starting her career over again at the bottom.
She loves flying & traveling, so she'd probably want to go to another airline.
So why didn't your girlfriend research the industry she was going into? Just because she loves flying and traveling doesn't mean she had to make a career out of being a flight attendant.
And it's not like she was a the top of her "career" anyway as a flight attendant, so what's the big deal.
Your sense of entitlement is disturbing, but pretty common.