The problem with what she says is that all it takes to make your brain more feminine is the wrong prenatal hormones at a certain time in development. Not necessarily long enough to effect the rest of the body. It's entirely possible to have a hyper masculine appearance, while having a female mind, or you can have several feminine traits and still think like a very masculine male. Nature is far from perfect, so it doesn't follow any one set of rules 100% of the time.
Having been in the womb with my twin sister, I was probably exposed to higher levels estrogen than normal. I'd probably be more feminine now if I wasn't forced into the male role(by myself and society), so over time my minds developed some masculine traits.
My arms don't go straight down like a males, which I suppose is going to prove useful when I begin to transition. My upper arm(12 in) is actually an inch longer than my lower arm(11 in). It was puberty that made my shoulders wider/broader than my hips, but only by 2 inches (circumference 38 vs 40). If it wasn't for the extra muscle they would probably be about equal in width. My hips still look wider than usual though, further accentuated by my somewhat feminine butt. My fingers are long and thin in appearance, so they make my hands look smaller. I can do the leg crossing thing, but that's because I'm very flexible and have a small frame. I still have body hair (it's not as thick as it could be, with some on my chest and abdomen). As for my face it does have some slightly feminine traits, so it's more a mixture. My brow ridge is less pronounced than most guys, but not really enough to be considered feminine either.
Maybe I have some degree of androgen insensitivity, some other condition, or some kind of hormonal imbalance.
I'm sure my body being feminine in some areas is related(at the same time not related) to how I think, but not in the way she claims. Most of my masculine mental traits are from learned behaviors to cope with what society expects of me. They didn't come naturally for the most part, so they still feel somewhat artificial to me.
In some ways she's trying to say that some TS people are better than others, and that if you don't fit a certain criteria your somehow less worthy of ever being happy.
She's trying to say that her method for training the voice isn't at fault, and that it's the fault of the mind. However, one method doesn't work for everyone, it has nothing to do with the mind being too masculine or not feminine enough.
~Marciel