She and most of her coven were executed by the Volturi for "attracting" too much notice from humans.
Hilda was born in Germany. After she became a vampire, she created the three women, Anne, Mary and Heidi out of pity for their poor lives.
Anne had a younger sister named Victoria, but she could not go back for her until she was strong enough to control her bloodlust. Once she became strong enough, Hilda gave her permission to go looking for her sister. She was thrilled when Victoria joined them. They lived happy lives, and 2 years later, Hilda added Noela to the coven shortly before the Volturi came and accused them of drawing too much attention to themselves. Hilda immediately came to defend her coven and allowed Aro to read her mind to prove them wrong; however, he still confirmed that they were criminals and Hilda was immediately executed, though she tried to argue.