I read in a magazine interview that on original reading Nichelle counted her lines and complained to Bennett. He asked her if she read the lines themselve. She admitted she didn't and when she did she was extremely happy with what she was able to do and was grateful for the spotlight Bennet put on her in that scene.
Yep. "Starlog" interview with Harve Bennett. Nichelle was also pressuring for a skirt version of the Starfleet uniform (in ST II) and he made sure that wish was granted for ST III.