If you try to describe Crusher’s character without mentioning (to use the RLM test) what her profession is, the costume she wore, what she looked like, or the fact that she’s a parent…and you are going to have a really hard time.
She is a gentle, generally quiet and very compassionate woman who, depending on the situation can display a surprising amount of civil courage and become very headstrong when it comes to helping others, even if she puts herself in danger. She enjoys theatre and dancing, and can be adorkable about that, but also tries to hide those aspects of herself from professional colleges and co-workers.
Not saying she wasn't under-developed, she was, but there was *some* character there that could easily have been expanded into more.