her submissiveness look less than a sacrifice and more like a proud role that she gladly accepts to take. 

I don't say that he's a great man. Willy Loman never made a lot of money. His name was never in the paper. He's not the finest character that ever lived. But he's a human being, and a terrible thing is happening to him. So attention.must be paid! He's not to be allowed to fall into his grave like an old dog! (Act One)

Second: Linda prefers Willy's happiness and comfort above her own. Linda is a woman who lives, like she says, "from day to day" trying to prevent Willy from committing suicide. She also lives "from day to day" trying to find Willy's soft spot, and trying to get his comforts; for example, her purchasing American cheese instead of Swiss just to give Willy "a change". Moreover, she is willing to hide her anxiety, sadness, and fear by, instead, singing to Willy in bed whenever he is the one who feels sad, scared, or anxious. We know that Linda is holding in a lot, because her humming is described quite pathetically. This happens in Act One when, in the middle of the night, Biff goes to the kitchen and finds Willy's rubber tubing behind the heater. This is another way that Willy plans to kill himself. Meanwhile, Linda keeps humming to Willy, despite knowing this too.

(Biff) is horrified and turns his head toward Willy's room, still dimly lit, from which the strains of Linda's desperate but monotonous humming rise.

Third: Linda's loyalty reflects in her quest to boost Willy's ego.

Linda is fully aware also that Willy is quite preoccupied with physical attraction because, in his mind, that is the key to success. Rather than blaming his lack of selling skills on himself, Willy blames it on his looks. He also blames everyone's strengths or weaknesses on how good, or bad, they look: on whether they are well-liked enough. Linda, as a typical loyal and submissive wife, reassures Willy of his looks, of his selling skills, of his parenting skills, and of almost every aspect of his life. By boosting his ego, she feels, is part of her wifely duties. 

Willy: I'm fat. I'm very foolish to look at, Linda. [...] as i was going to see the buyer I heard something about-walrus. And I- I cracked him right across the face. [..] they do laugh at me. I know that.

Linda: Willy, darling, you're the handsomest man in the world. [..] to me, you are. 

Hence, Linda takes the job of wife and mother to the extremes, sacrificing her own happiness and sanity in order to keep the family together. It does not seem like this is a tough sell for her, though. Linda seems to be quite proud and willing to do it. 

The character of Linda Loman in Arthur Miller's Death of a Salesman has the task of serving as the uneven foundation of a home where fantasy and reality are not quite delineated.

As a wife, she is the epitome of subservience and support. She even goes as far as placing Willy before her two sons in order to "save" Willy from fits of anger, or from any kind of humiliation.

As a mother, she has only had as much free reign as Willy has allowed her. Being the mother of two boys, Willy was very much interested in turning his so-called "Adonises" into successful replicas of himself.

However, Linda is not delusional. She is merely a weak follower of very dysfunctional men and, just because they are men, she feels as if all she can do is wait until they figure themselves out. The evidence that Linda is not delusional can be found from the very beginning of the play when she says the words

I don't say he's a great man. Willy Loman never made a lot of money. His name was never in the paper. He's not the finest character that ever lived. But he's a human being, and a terrible thing is happening to him. So attention must be paid.

Additionally, Linda does not deny the fact that Willy has tried to commit suicide although she has not told Willy that she has found this out. She tells her son, Biff, however, and she also tells him about the consistent hallucinations that Willy is having.

This being said, Linda is fully aware of her situation, but for the sake of the family prefers to use denial as a way to soften an otherwise horrid state of things. She cannot get away from it too much, for she knows that the life of her husband, and therefore her own future, is at stake. When she proposes that the men reunite altogether at the restaurant, she does this in aims that a miracle would occur and things get back to their regular place. When the meeting turns into a disaster, Linda is more than aware that chaos will happen next. She tells her two sons this much, allowing the audience to understand that Linda not always expresses everything that she knows, but knows more than we think.