Hi Danielle,
Currently we don't have functionality for Roles that can create child pages only as draft, it is something planned that we have not got to yet. Users with more permissions such as Admins or Content Admins can make pages and set them as draft and allow people to edit them as draft and then uncheck is draft when they are ready for the page to go live, but at the moment there is not a way to give someone permission to only create draft pages.
I expect we will get to this sometime in the course of 2012 but we have a lot of pressing priorities to get to so I can't say with any certaintly when it will happen.
Best,
Joe