It worked. In fact, she would follow me around whining until I got her frisbee from the garage after she released what I was doing. Sadly, River has no such focus and had to just watch us forlornly from the window with Starbuck exhausted herself by running all over the yard to catch and retrieve the frisbee.
Today, I decided to see what would happen with River. Before we started playing with the frisbee, if both dogs were out at the same time, they would encourage each other and run off of our property at high speed. This time, I had already spent time wearing Starbuck out, yet she remained focused on the frisbee anyway. Meanwhile, River took off at top speed. However, this time, realizing that her sister was not following her (or even paying any attention to her), she veered back towards the house rather than running out of the yard.
It was so nice to have the dogs running free in the yard for a while without them running off. They are so happy when they get to full speed--something that they cannot do in our enclosed dog yard. Watching them tear around the yard and leave divots in my driveway filled me with joy at their exuberant enthusiasm. Hopefully, this experiment means we can do this more often in the future.