one important thing I think is interesting in these letters (I am only on page 98, so..) is that slant indicates feeling - most people have a slight slant towards the right which is quite normal, a lil feeling, a heavy slant to the right indicates very stong powerful feeling whereas a slant to the left indicates literal holding one's feelings back.
for the most part her writing is no slant at all showing no feeling at the time but there are places that there is wild slanting both to the left and to the right -
will have to go back through to add specific examples but there are places in the first 10 pages or so where she talks about caylee and slants heavily to the left - trying very hard to feel nothing.
when she talks about CA betraying her, crazy right slanting - she was very upset.
she goes from feeling nothing to strong to nothing again often and this is the reason everyone thinks her writing is so different - it is not. her feelings are all over the place though.
fwiw it's extremely hard to analyze well on digital copies of copies