I concur with the idea to make the Destructor waste its rockets. Since it has already shot Lucy once, can we place her body in other positions as a decoy? What about the rest of the other EU-probe that we used for parts for Andrew? Do we have enough spare parts to build some decoys? That would take care of the rocket problem.
Now, on to other considerations brought up in messages below...
It is highly unlikely the C-probe has only one means of offense or defense. It has enough surface area that there could easily be more armaments hidden beneath panels waiting to be deployed once the primary system is exhausted. We also don't know if it has hidden capabilities of breaking out of tight spaces.
Have any of the probes tried to talk to it yet? Perhaps a transmission on the frequency of the ping could get its attention? I would suggest a remote relay transmitter just in case it decides to shoot at anything that talks to it. We might be quite surprised at the outcome. If nothing else, we may be able to convince Gail that it is a brainless behemoth instead of a kindred spirit.