How to Pre-Litigation Letter?

Sarah Crane was employed by Lawless, Inc. ("Lawless") for approximately five years as a computer programmer. Sarah always had excellent annual evaluations and received raises each year. Sarah is a transgender woman and began hormone therapy while working for Lawless. Sarah grew her hair longer and began wearing dresses and skirts to work. Sarah met with Human Resources and informed them that she was transgender and that she wanted to change her name on record in her personnel file from Charles to Sarah. Sarah's supervisor, thinking it was funny, occasionally called her "Lola" (obscure reference to a song by The Kinks). Her supervisor also regularly called her "Charles" or "Charlie" despite repeated requests to be called Sarah. Sarah complained to HR about her supervisor's repeated use of the wrong name, and also reported the instances where he had called her Lola. HR said that they would investigate, but Sarah never received an update about it. However, shortly after her meeting with HR, Sarah began to notice that she was not getting the same job assignments that she used to get. Significant amounts of work were being given to other programmers, even employees with less seniority. Her supervisor continued to call her by the wrong name. One day Sarah's supervisor called her into his office and placed her on a Performance Improvement Plan ("PIP"). Sarah had never received any warnings, write-ups, or comments about her performance prior to reporting her supervisor to HR. Approximately one month into the PIP, Sarah's supervisor brought her in for another meeting and told her she was being terminated. Her supervisor stated that it was just not a good fit.