I run a game for two of my kids right now who are 11 and 13 years old. They do well with AD&D 1E and love the game.
I have a newly minted 8 year old though who is dying to roleplay with her brother and sister but 1E is beyond her by just a bit yet. Give her a couple more years and I think she will be fine.
Having said that, I was interested in taking on an adventure of my own and creating a version of an rpg that is influenced by AD&D1E but much simpler, more straight forward. Think Monopoly Jr and some of the other Jr versions of traditional games that have been out for a few years now.
I have a 5 page PDF that is the beginning of my effort at AD&D Jr. I would like to get some input on it.
Download it here and let me know what you think.