I honestly doubt there is much in the "diary". I have two girls who were both 7 in the last 4 years, and they both had diaries..it was little drawings, I love my family, my sister is mean, Dear Santa I want a puppy.. mostly misspelled attempts at very child like themes..not only my kids, but of all their friends and all my friends who also have kids I have NEVER heard of a first grader with an "older boyfriend"..kids this age think anyone out of their grade is a baby, and anyone older is a big kid..there is not much intersex mixing outside of siblings at this age..this is FIRST GRADE we are talking about, not a 13 year old who will write about crushes and family problems...boys are "yucky" until at the least fourth of fifth grade... I understand that children this age can be molested, or can engage in "doctor" play etc. with close relatives or friends, but to be in first grade and having a "secret older (consensual) boyfriend" seems like a far-fetched idea to me.
I also believe LE was all over the family and would have zeroed in quickly on any neighborhood claims of mistreatment by babysitters or abuse. I believe the one mistake in this family was that the children were allowed way too much freedom for their ages, there was not sufficient supervision, but I wouldn't by any means consider these to be neglected or abused children...IMO when you see this type of lack of supervision and it is in her own neighborhood, when the family moved apartments in the same complex in order to have a ground floor closer to the playground (that was mentioned in MSM earlier link), I think the problem is the family felt a false sense of security and was even naive, but I do not think this is abuse or neglect in any way.