AWDImpulse,
The part number should be on the timing belt cover. With NGKs, the last numbers are the plug gap in milimeters. For most Civics of this vintage, the gap should be 1.1 mm or 0.040 inches. I'd suggest using the NGKs as they are pretty cheap and just seem to run forever.
The plug gap should also be in the owners manual, if she has one and might even be on the sticker under the hood.
Bogatyr