Tara Reade worked for Joe Biden's Senate office between December 1992 and August 1993, after which, she voluntarily left the job. She recently claimed that he sexually assaulted her while she was working for him. While definitive evidence for or against this claim is extremely difficult to obtain, a concurrent claim she has made is that Biden's office retaliated against her after she made some kind of complaint.
While journalists working with Reade have been able to uncover some documentation of her employment history (see above links), other hurdles have made it hard to piece together the facts. Former interns for Biden have confirmed aspects of retaliation claim. Reade's mother called into Larry King Live shortly after Reade left the job to ask what a Senate staffer could do about "problems" with a senator. While all we have is a recorded human voice which Reade personally identifies as that of her mother, there is corroborating evidence for this identification such as the timing of the call and the geographic origin of the call.
Question: What other testimonial or documentary evidence exists regarding the circumstances of Reade's employment in the Senate, the nature of her responsibilities and how they may have changed over time, her relationship with supervisors and fellow employees, and any other facts which may be relevant to verifying Reade's claim of employer retaliation?
EDIT NOTE: This edit reflects an attempt to address issues raised by fellow SE users that led to a vote to close. I have attempted to make the question focus as closely as possible on objective and verifiable facts.