A couple of years ago I went to an Explore Learning event in a library which was being held on the subject of Alice. Explore had confused Through the Looking Glass with Wonderland and had a mixture of the two plots for the children to put in order. The group leader had no problem putting hers in order because the sequence was on her instruction sheet! Most of the children found it quite easy though their answers were inventive! (They were Y1s from various schools.) The only person having any difficulty was me. When I complained I was told that was the way it was and the sequence must be correct because the leader had a printed copy.
So, I don't think five and six year olds (or younger in our case) have a problem with Alice. (Though the staff at Explore Learning do.)