Continuity mistake: When Billy and Kate return to the Clamp building as the Gremlins hatch, look closely - Kate is wearing beige/tan colored pantyhose/tights in the first scene of them running to the building. ("How long do they take to hatch?", "Not long enough, come on!") Almost immediately after arriving, Kate is told to begin her duties as a tour-guide, and thus doesn't have time to change her outfit. However, in one of her next scenes, she is suddenly wearing brighter cream-colored pantyhose/tights. (And given her fairly consistent screen time as a tour-guide, it's clear she didn't have time to change this one part of her outfit).
Continuity mistake: The pots inside the microwave during chaos in the kitchen change positions between shots.
Continuity mistake: When the crazy Gremlin pops out of the pot, his right arm swaps between being covered in noodles or not, back and forth between shots.
Continuity mistake: When Marla is trapped in the web, she either has a huge web in front of her, or nothing at all, depending on which angle is focusing.
Continuity mistake: When attacked by the flying gremlin, the running blood on Futterman's forehead and face decreases between one frame and another.
Continuity mistake: Billy uncovers Gizmo's cage but a frame later the cloth is back on.
Continuity mistake: When Billy asks Kate to pick Gizmo up from the drawer, the white bag next to her keeps changing positions between shots.
Revealing mistake: When the female Gremlin shows-up, there's a fuss in the lab and a Gremlin is throwing stuff. The wires on his arm are visible.
Continuity mistake: When Gizmo dances in the lab, Martin and Lewis look at Gizmo on the right. A frame later, in the close-up, they are looking at an empty left side. Then the angle changes back to first shot.
Revealing mistake: When the Chinese store is being demolished, a wire is visible on Gizmo's left ear.
Continuity mistake: When Clamp is talking about making Gizmo merchandise, Gizmo's hands swap from being on the side of the box to on the center of it, between shots.
Continuity mistake: When Futterman covers the Gremlin in cement, the red truck behind swaps to a golden car.
Continuity mistake: When the yuppie gets catapulted out of the revolving door, the blonde woman he crashes into appears out of nowhere between shots.
Continuity mistake: After the bat-Gremlin gets covered in cement, it takes off and, a frame later, all the cement is gone, only to reappear when the Gremlin settles on the church's roof.
Continuity mistake: When Gizmo grabs the remote to watch Rambo, a black chess piece next to the cage swaps from standing up to fallen between shots.
Continuity mistake: When Clamp is shredding the Gremlin, the amount of green flesh around the blades decreases between the first and second shot.
Continuity mistake: Marla holds a cigarette in her right hand. A frame later it's gone and both of her hands are crossed.
Continuity mistake: Futterman places the red slide with falling cement inches away from the Gremlin's head. In the close-up it's gone.
Continuity mistake: When Billy frees Gizmo, the pen on the desk changes positions between shots.
Continuity mistake: Whenever a complete image of Gizmo appears walking or dancing, the puppet is 10 cm taller and way chubbier than the one commonly used. For example, when he dances in the lab, count the metal squares in the cage: He grows from a height of 6 to 9 between shots.
Answer: She only saw him briefly, never in full light either. Plus, it was some time ago. I don't think she would suspect there is another one either.
lionhead
At the end of the first movie, after killing the gremlins, everyone is at Billy's house, and Kate puts a thermometer in Gizmo's mouth and looks directly at him while doing it, giving her plenty of time to look at him.
Still, very briefly, still in low light. She has had way less interaction with Gizmo overall.
lionhead