O.K. This is a rewarding activity for Winter. She believes that at times of excitement she is encouraging you to do what she wants you to do faster by nipping.
Try this for a week and get the rest of the family to do it too and I garuntee you will see a massive improvement.

As soon as Winter attempts to nip, even if she makes no contact, the person on the receiving end should stop dead, cross their arms and stare at the ceiling (sky if you are outside). Continue to do this until she looses interest and turns away. Be careful not to speak or look at her until she has turned away - really given up on the whole idea, not just circling for another go. When she does turn away continue with what you were doing as if nothing happened. She will quickly learn that her behaviour achieves nothing and things only happen when she restrains herself.

Let me know how you get on.