Bjoern you are right that she makes a point not to dwell on the whys of sickness (that possibly lead to guilt) and she is very explicit about this, emphasizing that it can never be known and to trust a higher power. I really appreciated this too and you are right to remind me of this.
It still seems though, that she is saying that specific diseases (and their location in the body) are related to specific life crises (spiritual is the example I used before). To me this suggests you examine this dimension of your life because it is what needs immediate attention. This is where I get a little lost and maybe I am taking her too literally because that creates a bit of a paradox to me--offering a why when it is impossible to know why? I didn't mean to sound negative and again you are right that she does explicitly emphasize not asking why or figuring out reasons for illness because it is not something we can solve, that instead we should shift our focus to prayer.
She also wrote that karma is very real. Again, here I feel like we are in tricky territory. I really liked Sogyal Rinpoche's explanation of Tibetan Buddhism and the concept of karma in his book "The Tibetan Book of Living and Dieing." I remember one passage specifically where he talks about how Tibetans view difficult life circumstances like illness. He wrote that their is no judgement passed when a Tibetan sees someone suffering, though it is viewed as karmic. Instead their is a saying in Tibetan along the lines of: through this suffering bad karma (if that is the term) is being 'swept away wiping the carpet clean' (sorry I wouldn't be able to find the original quote). In other words, everything accumulates through many, many lives and eventually you have to wipe the slate clean--there is no way to pinpoint why illness and suffering happened and they don't try. Of course SR's explanation is much clearer, knowledgeable and well-written.
The point is I am trying to wrap my head around what these people are saying and so my questions about responsibility for illness extend beyond this lifetime, even though I have no certitude about what lies beyond death, if I am being perfectly honest. Both of these writers/teachers point to perhaps, complete (?) responsibility of one's condition in a karmic sense, but not to dwell on it because it is a mystery of the cosmos that will never be answered, and to keep prayer immediate and central, that things can change or at least our perspective can--and that spirituality is important.
Not asking why and keeping prayer central seems pretty healthy to me.