First, yeah, like people in DC seeing a prostitute will not give the name of Congressman and Senators. I'm sure she's had at least 6 Ted Kennedy's as clients.
If she had names, she'd just use them. There's nothing a Congressman can do now and the prosecutor won't care that names are exposed.
She doesn't have names, she has records of phone calls (phone numbers, dates, and times). This information readily leads to lots of other information.