Quick Reading

So my 6-year-old daughter picked up Wonderland and wanted to read it.  She is not my reader; the 10-year-old is by far.  But it was a graphic novel and I was unsure about the story so I picked it up and began reading it. I am very close to the end in a little under an hour and it has been fine content-wise for her so far.

Here’s my question: At what point did you let your kids just read without checking their material?