Hydramethylnon is a trifluoromethyl aminohydrazone insecticide. It is poorly absorbed from a dog's gastrointestinal tract, more than 95% is excreted in the stools and not absorbed.
The most common signs reported in dogs with oral ingestions of hydramethylnon are gagging and vomiting. But we only need to induce vomiting if large amounts (greater than 1 ounce of bait per kilogram of body weight or 0.45 ounces per pound of body weight) are ingested. That means if a 10 pound dog eats less than 4.5 ounces she should not get sick.
According to the manufacturer of Combat Roach Control System (1.65% hydramethylnon) a medium-sized (4.545 kg or 10 pound) dog would experience adverse effects from the bait itself only after eating an amount equivalent to 50 trays. The concentration in the trap she ate was even less, and she didn't eat the entire trap. That means she should not get sick.
I was more concerned that she ate the plastic, which can be very irritating to their gastrointestinal tract and could cause an obstruction, so I am relieved to hear that isn't a worry.
Dogs are attracted to these traps as they contain sugar as a bait too, and dogs have a sweet tooth. So I'd throw away the rest of the bait stations (if there are more), but she should be fine.
Please let me know if you have any further questions.