She's back again! The boys and I watched the northern water snake catch and eat one frog, but she kept hunting for more. So I ran to get my camera, and took a video of her hunting along the edge of the pond. What neat behaviors! She does a lot of poking around, lunging onto land, and wiggling her head back and forth.
She does not seem to mind us too much, in fact before I took the video, we all got to pet her. I think she's starting to associate us with food.