How to I enjoin a person from contacting my employer?

I am employed as a independent contractor with a real estate firm. I also have a DBA which I use for other business services that I offer. Under my DBA I was providing property management services. A client of mine who 2 years ago attempted to defraud me is now claiming that I embezzled money from her and has contacted my employer. She refuses to sue me directly (probably because she knows she will not win) but has gone after my employer demanding payment claiming I overcharged on maintenance. My employer is evtremely litigation-adverse and has threatened to terminate my contract and is requesting I produce all the documents on the 10 properties I managed a little more than 2 years ago showing all expenses and receipts of services charged. This would be extremely burdensome to me in that I clear out all documents every 2 years and would have to contact each and every company that did work on the property (some of which may have gone out of business already.) My prior client has not brought forth any such evidence and my company is putting on the burden on me to produce them. Is there a way I can obtain a court order or something to stop her from contacting my employer?