What Causes Leg Weakness, Borderline Syncope, Clammy Skin, Vomiting And Head Pressure?

my mother in law was standing and chewing at the same time. She felt weak in the legs and had to sit down with a borderline fainting spell. she recovered slightly with clammy skin. this lasted for 30 mins and had to rush to bathroom to vomit. She came back out for another 20-30 mins and had to vomit again. she complains of head pressure but no stomach pain. Did she trigger a nerve with her jaw while eating or is it something else. She shows no signs of stroke as her speech, face and extremities are all normal