I tend to think so too, since she just happened to be in town at the time of Levy's disappearance. Here's my speculative scenario (since speculation seems to be the order of the day around here):
Chandra had told her folks that 'something big' was about to happen. Also told her landlord back in January she expected to move in soon with her (ahem) 'boyfriend'. So, she goes to meet Mr. and Mrs. Condit for the showdown, where the happy couple break the news to Mrs. Condit that it's over for her. The Mrs. freaks out, pulls a gun a shoots Chandra in a jealous rage. They keep the body somewhere for almost a year, then dump it in Rock Creek.
Plausible, you have to admit. Maybe the DC police should carefully check Mrs. Condit's hotel room for bloodstains.
For WHAT? Having sex? Gimme a bleeping break,here! His wife had been living in Ca the whole time he had been a congresscritter,and he lived in Va or DC the whole time. They rarely even saw each other,and this seemed to suit them both just fine. She knew he was boinking other women,and didn't give a damn.