Is Reira's shield going to do diddly? No, but it was better than sitting and gawking and in a weird way felt better than just standing about. When she feels herself ping blue however, she finds her current shield position a bit silly- what with now launching up to wherever Papyrus feels is Safest. "Oh-!"

.... "...ok..." Her shield is still up, mostly because she has quietly entered a strange foggy state of shock as she floats about.