I'm hoping that there are some xNFP mothers out there that can relate to this and, after going through this themselves, offer advice.
My girlfriend (24, eSFJ) and her mother (50ish?, INFP) are a case study in extreme Fi vs Fe. We'll call my girlfriend Sarah and her mother Jane (I'm sick of typing "her mother" and "my girlfriend" etc repeatedly...).
Jane, as the Fi that she is, simply does not consider the emotions of other people when forming, expressing, and dealing with hers and others' opinions. Regardless of how rational/logical/well-thought-out anything Sarah does is, her mother will express how horrible it is until she herself comes to the same conclusion.
So, whenever Sarah brings anything up and is distressing to Jane, Jane will strongly assert her opinion that it is horrible - and so are all the people that were involved. When Sarah got an apartment, it was obviously her best friend's bad influence on her so her mother then hated and demonized the best friend. When Sarah bought a car, it was obviously her "power-hungry" friend (me), so she demonized me. When Sarah has a boyfriend, such person is the most evil person in the world - so much so it justifies long notes talking about how they're just going to use her and force her to have sex and give her STDs and just completely dominate her life and suppress her free will (note: this is NOT an exaggeration).
So then Sarah turns around and argues back... But then her mother [appears to] completely shut down because she can't deal with the destruction of her internal emotional balance. So then Sarah, the Fe that she is, backs off because there is now external emotional disharmony. Consequently, she simply cannot (and never has been able to) talk about any serious issues with her mother because her mother will explode, demonize it, and then be unable to process a response.
So, naturally, her mother doesn't know we've been in a relationship since last July.
If Sarah's father (INTJ, probably) were still alive, it would definitely help, but he passed away about three years ago (I think). (Note: of all possible ways a family can lose a husband/father, the way that he passed away was the least traumatic.) (Note #2: her mother's behavior did not change at that point. It has always been this horrible.)
I intend to ask Sarah to marry me. We both want this, but we agreed at the very beginning that it will not happen until her mother knows... And she still doesn't.
I would greatly appreciate ANY ideas ANYBODY has about telling her - especially if you have been in the position or a similar position to Jane.
Thanks in advance!