It depends on the exact type of statements that were made about you. Generally speaking, defamation consists of statements of fact (rather than opinions) that are communicated to other parties and cause harm to reputation. A statement of fact is a statement that can be proven to be true or false. However, "truth" is a defense to a defamation lawsuit. A defamation lawsuit is extremely expensive to prosecute and defend. Contact a local Florida Defamation Lawyer to determine your rights.
As you are describing the events, it seems that this is a personal issue with you and the other individual. While you may obviously sue her, it would be another issue to hold the employer responsible unless you can prove they were complicit with her or directed her to say such things.
Dear Boydton Beach - your case sounds like that person has said sufficient falsehoods about you, to third parties, which impugn your truthfulness and ability to do your job. You will need to determine exactly what she said and who heard it. If you cannot remember all of what she said, a few specific statements are needed. You will likely only be able to sue the person who was speaking and not her employer. Get a local AVVO-rated lawyer to help you move forward. The process is complex and you will need help. Good luck.
In this question, the word you need to focus on is DAMAGES. You as the Plaintiff must prove monetary damages. Certainly people say things that are both demeaning and mean spirited. However, a Jury will not award a penny for hurt feelings. Defamation must lead to some tangible damage like loss of employment or identifiable mental distress. This is challenging and expensive to prove. The problem is unless you are Tom Cruise and can prove a loss of revenues, these allegations are going nowhere.