You might try making it loop forward and then reverse it, so that she moves the glass up and down. Though you'd likely have to increase the length of time between frames. It makes the gif file size larger of course, and you might have to reduce the size of the images. I went through 3 or 4 versions experimenting with timing to get my current one. It's definitely tricky with these things. I wanted two transition frames between each main photo, but had to settle for one transition.
Or maybe you could simply repeat each frame, that might slow it down a bit.
If I'm ever able to get the TOS series, I might modify mine again with scenes of Skip from Patterns of Force.