Why Campion's Janet Frame biopic misses the mark

Jane Campion's film about the life of the New Zealand author Janet Frame - originally a 3-part TV series, later distributed as a 2.5 hour movie in 3 parts, An Angel at my Table - based on Frames three-volume memoir (the title is the title of Frame's 2nd vol.) - has many of Campion's strengths as a director, and some serious weaknesses, unfortunately (I watched only the first two parts). Campion is great at establishing a historic period and giving us a vivid, almost tactile sense of the hardship of life for a large, working-class family struggling to get by in a remote NZ town in the 1940s: the cramped bungalow, with 4 girls sharing a mattress, the dismal outhouse, beautiful mountain scenery all around but the living conditions bordering on squalor. Also she gives us a good sense of Frame as a young misfit, strangely homely, awkward with others, withdrawn, lacking in social graces and boundaries (in one powerful scene completely misreading a whole situation and letting the family know at dinner that she saw her older sister "fuck" the boy next door). So the first section is pretty good, especially in that we know we're seeing a portrait of the artist as a young girl. The second section or chapter really misfires, however: in this section Frame goes off to college (in Christchurch, I think) to pursue her dream of becoming a writer. At one point in despair she tries to kill herself w/ an aspirin OD; a well-meaning but feckless teacher suggests she go to a hospital, which apparently leads to a misdiagnosis of schizophrenia and 8 years in an institution under-going hundreds of electroshock treatments. I say "apparently" because none of this is dramatized, Campion skirts over that entire section of Frame's life (she may have done the same in her memoir), and the next we know she's out, living in a rural spot with a fellow writer (a mentor, not a partner) and writing - and lo and behold her first book is accepted on first try! But what does she write about? We really have no idea (and from the little I've read about Frame I think she was published pretty widely before her hospitalization - the movie seems to distort her chronology for dramatic effect). Too much left unexamined and unsaid her, and Frame in part 2 is just a blank canvas. I really want to know more about Frame, but will have to go to her books for that to happen (maybe that's as it should be).