This is a gold digger! She has no case under Georgia law because there are no statues regarding the spreading or exposure of herpes. She has a case under Louisiana law but the law is as following:

A person convicted of the misdemeanor of infection of another with an STD (as defined by Louisiana law) may receive:
a fine of up to $200 for a first offense
a fine of $25 to $400 for a second offense, and
a fine of $50 to $ 500 for each succeeding offense and/or imprisonment for not less than 10 days nor more than six months.
(Louisiana Rev. Stat. Ann. §40:1068.)

I think Usher should fight this or he will face multiple lawsuits from past sexual partners and other gold diggers jumping in on the bandwagon (anyone that has worked with him could jump in on the bandwagon for some money). It is better to let a judge decide the outcome than just coughing up money to someone that may or may not even be infected.