What is Linda's role as a mother and wife in the family?a little more details will help me understand more, instead of a one sentence answear.

As a wife linda protects her husband's emotions and dreams. She refuses to see through Willy's lies. She accepts the american ideal that success is possible for everyone. Linda shows substanically more preoccupation than her husand with talent, dedication, and basic ethics which reach beyond simply being well-liked. As a mmother she expresses her concern over biff's poor performance in maths, his growing aggression, and his tendancy to steal everything. 

When Biff complains about his father's erratic behaviour Linda proves her devotic to her husband by telling her son " Biff dear, if you don't have any feelings for him, then you don't have any feelings to me", and "He's the dearest man in the world to me, and I won't have anyone making him feel blue. " As a mo ther she knows that her son Biff is atleast one source of agony to Willy , but throughout act one, Linda chastises her son for not being attentive and understanding towards Willy. 

Linda believes that if her sons become successful then Willy's pysche will heal itself. She expects her sons to manifest the corporate dreams of thei father not because she believes in Willy's american dream, ,but because she belives in her son are the only hpe for Willy's sanity.

She behaves as a perfect wife and mother throughout the play. However, this lifestyleof hers ultimately leads to downfall of her husband.