There may be a reason DW sleeps on the side she does, but I'm not aware of what it might be.
Back when I used to sleep with beautiful young women (I was young, too), I was always on the left side from the foot of the bed because I'm right-handed (Whoops! That's TMI for this group! ).
Nowadays I sleep alone, which guarantees a good night's sleep.
BTW: a woman I slept with many years ago snored like a longshoreman. It was incredible.