Hi byran,
From your question you seem to be confused by sleep facing and bed headboard. When we talk about sleep facing it mean when you lay down sleeping your head must be pointing to your favourable position or in another word it is also your headboard pointing direction to the wall.
It all depend on which of the 4 best directions you are looking for. For a child, I will suggest personal growth and if you have health problem then you go for Health if not usually we go for success.