Moral dilemma: If you were in this situation?

A really annoying neighbour has just popped 'round (again) so she can chew my ear off about herself. I just made her a cup of tea, and she has put it down on the back step while she follows me around the garden as I try and clear up. Out of the corner of my eye, I've just seen Belinda drink from her cup. Belinda is a chicken. The neighbour has gone home to fetch her holiday snaps. Shall I make her a fresh cup of tea, or pretend I didn't see the chook behaviour?