Hello,
Sudden drooling is often a symptom of a infected tooth or something lodged in the teeth, gums or throat. What I would recommend is to look into her mouth again, check the teeth over carefully and gently push or press on them to see if any are tender or cracked.
If you see nothing then she will need to see the vet. Drooling is also a symptom of poisoning so if she could have gotten into anything then do not hesitate to take her straight to your vet. Check around the house, the yard etc to see if there are any toxins she could have gotten into.
Another cause could be from plaque and tarter build up on the teeth. Does she have a large amount of plaque or tarter? If so this will need to be cleaned off as this can cause infection and the plaque and tarter is toxic in large amounts.
Walter
Breeder
Breeder and pet health consultant. Have spent a number of years with dog rescue, training and health