I am not sure what effect you want to achieve. I think the first one is cool though. The long shutter speed doesn’t do anything for you on that shot. The entire exposure was all flash. You would have gotten the same shot at 1/200 sec. If you want to try something different try the long exposure and do some light painting with an LED flashlight. You can get a softer look around the edges and try just a touch of light to show some facial mood. You could do a long 30 sec exposure if it’s dark out and paint away. You could also freeze the rain with a speedlight to finish it by aiming it off to the left and right of your subject standing behind her.
You might also try using a bright background the meter off the face and under expose the face by three stops. That should make it dark.