Tamm was well-known and liked by her neighbours for her magical abilities. She gave birth to a daughter, Thaegan, toward the end of Queen Elspeth's reign. Thaegan quickly grew bored with her mother's simple life and fled into Deltora's northern mountains, only to return seven years later even stronger than before. It is unknown what became of Tamm after Thaegan's reappearance, however it is possible that she was eaten alive by Thaegan as her daughter's favourite food is revealed to be living raven in a riddle provided to Lief by the Enigmatic Giant.
Thaegan went on to become one of the most feared beings in Deltora's history, second only to the Shadow Lord himself. Over a century after Thaegan's birth, Tamm was mentioned by Josef in Thaegan's section of the The Deltora Book of Monsters.
Tamm was a gentle, kind individual, the opposite of her daughter in nearly every way. She was exceptionally fond of animals, especially birds, and she was popular because of her magic. Thaegan broke Tamm's heart when she ran away. It is not clear why Thaegan bore so much animosity toward her mother, other than simple spite.
Tamm was a talented sorceress, though she was nowhere near as powerful as her infamous daughter. She was particularly skilled in the creation of love potions and healing spells. Tamm was famous for her ability to transform into a blackbird.