B.G.
If I'm being redundant, I apologize. I didn't take the time to read other's postings. I think it's probably similar to the children who hold their breath when they are mad or in trouble. My mom held her breath as a child and would sometimes pass out. Try ignoring her. She may be doing it because she gets so much attention from you (even negative attention). They seek any sort of attention. Next time, walk away to a place where she thinks you can't see her. If she stops, you know she's just putting on a show.