Samantha Smith was the third assistant director on Revenge of the Sith. She was also a set production assistant on Attack of the Clones. Since Sith Smith has worked as second assistant director on the TV Mini-Series The Pacific and the films Great Gatsby and Jason Bourne. For Mad Max: Fury Road and Gods of Egypt she was the key second assistant director.
If you’re wondering what assistant directors do on a set I highly recommend watching the Revenge of the Sith documentary Within a Minute. You can watch it below, or find it in the extras on a blu-ray or digital version of the film. The section on the directing team starts about 26 minutes in and you can see Sara Smith at work on set and hear from her in this section of the documentary.
The more complicated the film, the more assistant directors the film will need.
Check out the entire list of women in 365 Days of Star Wars Women in the Women in Star Wars Index. It includes highlights from each post plus notes which posts include new 365 interviews with actresses, writers, artists, and more.