My opinion, and please correct me if I'm wrong, but........ If I'm a required crew member, wether I'm in the left or right seat, FP or NFP, I'm allowed to log everything- night, instrument, inst-approaches, X-country, everything, except PIC (if I'm NOT the one in command). If you are the NFP, you're still part of the flight-crew, monitoring the FP, making your calls, double-checking the approach-plates, not to mention your ass is just as much on the line if you bust an altitude or MDA. You have every right to that instrument time. I'm not an FAR expert, just what I think.