Approaching a dog in a home where you have been invited, where you assume your best interest and well being is upheld by the person who invited you in.
Completely different story!!
Point of the matter the OP now has knowledge that her dog, as she stated had never shows aggression before, can get a bad temper when people are a bit full on before she gets to know them.
Now It is her job to warn people, correct the behavior in her dog and make sure that her home is a safe enviroment for who ever is in it human or animal!