It sounds like you're doing great. Keep reading/watching as much as you can especially on the signs and what to do if the foal is in the wrong position and red bags. You might want to start setting an alarm and getting up every 2 hours to check on her then 1/2 hour or so as she looks closer, which looking at her will be soon. Especially if she's never had a foal before you want to make sure you are there in case she is scared of the foal and/or can't figure out what to do. Don't get me wrong, even if it's foal #10 you want to be there to make sure everything goes well. Don't worry about asking anything, nothing is too minor or stupid. Can't wait to see the little one!!
Oh, if she's going by the book I think you're waiting till her nipples point down instead of in. Is her udder going down at all when she's out for the day? That would be another indicator she's really close when there is no change in her udder after she's been out moving around.