529 Funding, Room and Board for Students Living at Home and A Couple of Curve Balls

I'm trying to determine how much of my children's 529 accounts I can use for room and board expense, if any.  
 
My son is a part-time student at a local college and lives at home.  I have the figures from the college for COA R&B for students who live at home, but I don't know if funding these expenses via a 529 is subject to minimum course hours per term or any other determinant of matriculation status.  
 
I also have a daughter who is at the same college.  She is attending as an early admit student through her high school.  She has not yet graduated from HS, but is attending the college full-time and completing any necessary HS credits through the coursework she is taking at the college.  She has a college ID and she registered at the college for the coursework.  Presumably this means that she was admitted, and that seems to be borne out given her status as an early admission student, but I'm not entirely sure about this point.  She, too, lives at home.  The same COA R&B figures are applicable, but in this instance the question is whether she should be seen as a college student or a HS student.  Presumably if she can be treated as a college student, there isn't any issue in funding R&B out of her 529.  
 
If R&B funding is appropriate, can I take R&B for both of them from each of their 529s?
 
Thoughts?  Comments?  Other considerations?