I have a feeling the reason the defense allowed these to be released, is to elicit sympathy both from the public and the jury pool, for Casey.
Now, I can understand a bit more why the family has been behind her.
They didn't want all the (allegedly) horrible things they've done to come out and
hope(d) if they stood by her, she'd be quiet about their deeds.
I seem to recall a jail visit where Cindy was concerned about a recent doctor/psych? visit with Casey and she said "Don't worry, I didn't tell them anything."...I am paraphrasing.
I don't feel sorry for her but I'm understanding her a bit more. I also don't think she's telling the truth about everything, although I think enough of her real personality leaks through as to give insight into her character.
And yes, her handwriting is difficult to read, just as her personality seems to be.