I find it strange that its easer to obtain the long stay visa on retirement while in thailand than out. And you dont need to worry about the insurance.
She should apply for a 2 month visa in NZ before leaving.
If she wants to stay in Thailand longer, she can get a extension at cm immigration, how long would she get 15 or 30 days?
Other option is that she flies out to South Korea and when she returns to CM, she would get a 30 day stay, can this he extended and how long 15 Or 30 days