checking on here quickly,
http://www.forestdhamma.org/books/english/
silaratano was the translator (thai to english, original thai maha boowa) for the mae chee book, ajahn mun bio, and arahatta magga/phala.
as i recall the intro/preface/beginning section for the mae chee book explains what parts were fictionalized to give her life story continuity. mostly mundane life details like what a young farm girl is thinking about her life and aspirations. i think the meditative part you quoted about anagami should be in line and directly quoted from maha boowa’s many works, so i don’t take it as a grain of salt, i take it as an english translation of an arahant’s words. in other words, my guess is i think there may be compositing from different dhamma talks so it may not be exactly what mae chee said, but the composite would draw from real anagami experiences of ajahn mun’s disciples. just my opinion.