In the Disney animated movie Frozen, when Anna was still young she was struck accidentally by Elsa with her Frost powers and froze Anna's heart. Anna was brought to the Trolls by her parents to heal her. At that time Kristoff saw how the trolls healed Anna.
Now when Anna was pursuing Elsa, she was again accidentally struck by Elsa with her Frost powers. Kristoff then brought Anna to the trolls again hoping that they could do something about her.
Now my questions are, did the Trolls know that it was Anna, the same girl that was brought to them a few years ago? As well as Kristoff. Did Kristoff know or remember that it was Anna that he saw few years ago healed by the Trolls?