Perhaps got decay teeth, get her to see dentist, but pls note that the insurance will only cover emergency treatment. Better check w/ insurance company first.
Perhaps she got digestive problem, get her to see doctor
Perhaps she has not cleaned her teeth properly. Get her to attend a toothbrushing and 用牙綫 lesson (perhaps taught by you!!)
before receiving any dental / medical treatment or attending any lesson, get her a mask and insist her to wear that during working hours, that can prevent the whole family from inhaling 沼氣而中毒!