The officer should have subdued her with appropriate force, placed her in hand cuffs, called for backup and taken her away to jail. Last time I checked, assault on a police officer was a felony as is resisting arrest, which I'm sure she would have committed once being placed under arrest.
Unfortunately, the one part of the US Constitution that every congresscritter has committed to memory is Article I. Section 6: ".... They shall in all Cases, except Treason, Felony and Breach of the Peace, be privileged from Arrest during their Attendance at the Sessions of their respective Houses, and in going to and returning from the same;"
Also, unfortunately they have substituted the word "including" for the word "except" in common application of this item.