Hey, I know it's been a long time since I rapped at ya (this morning), but I'm further in the book since then.
The general impression I get is that Cain simply wants to be liked, and does not deal with criticism well. If that sounds harsh, then temper it with the fact that you, me, and everybody else in this thread is most likely a nobody who won't come close to having the experience she had and is currently dealing with.
Some Cliff Notes after about two hours of the 9 hour+ audiobook:
* She is extremely harsh toward her high school coach, who she simply calls "Mitchell" (I'm not sure if that's the correct spelling, but apparently it's his last name). She claims that he talked openly about other teammates' sex lives and use of alcohol. She is maddeningly unspecific in this claim. (Simply saying at one point, "He asked for it." Without clarifying what question or questions provoked such discussion.)
* She does not get along with her female teammates. Many of them have parents who say mean things to her. At one point, Mitchell allegedly tells her she will never be team captain, as her teammates do not respect her. She also faults Mitchell for not intervening when parents hurl abuse at her. But, before you check "personality disorder" on your bingo card, you should watch (or rewatch) "Mean Girls" first. She is intensely competitive, and it causes problems in her personal relationships.
* She also talks openly of supporting her teammates, despite having a target on her back due to her massive talent. The most enlightening chapter (so far) is chapter 27, in which she approaches a (n unnamed) competitor and suggests they warm up together. She loses the competition to this fellow athlete, but is proud of her performance and shows a great deal of humility (she "gave it her best shot" and doesn't feel robbed when she loses).
* Message boards, and specifically Letsrun, are mentioned. She finds the comments on them so distasteful that she claims not to read them. But, she knows, for example that some people claim she is biologically male (in the book, it's a tad more brutal: she has a penis; she briefly discusses her delayed onset of menses for no other apparent reason than to disprove this ludicrous claim). Mitchell, on the other hand, reads them. It's another one of his character flaws, we should suppose.
* She narrates the book herself, and, while it takes something other than running talent to give a good audiobook performance, she does an admirable job. There are parts where she becomes choked with emotion and even begins crying. The effect is pretty stark and should help anyone who hates her see her as human.
* Her introduction to Salazar is cordial and she clearly had a lot of respect for him as a coach at one point in time. If you read between the lines, you get the sense that she has a crush on Galen Rupp, which is pretty normal and kind of sweet. Like, there's a real in person in there dealing with real person issues, just under a glaring spotlight.
More later...it's a worthy read, no matter what you think of it's author.