According to Alea, she is a good wife. Abandoned by her husband, she has been left to raise six children, which most likely gives her the unfriendly attitude. She seems to have, as Astrid points out, "Quite the mouth on her." She demands to be set free when talked to.
Choosing to kill Alea, Astrid congratulates the Dragonborn with, "Ah, the feisty goodwife. Quite the mouth on her. Someone must have wanted her dead...right?"