1) Her neglect in confronting her Willy when he brags, "I did five hundred gross in Providence and seven hundred gross in Boston"(35), especially when she's smart enough to realize that the gross for the trip is actually two hundred, shows that Linda is attempting to protect Willy from himself. She sees what's going on, but she refuses to call him on it. Is this her weakness as a partner? Maybe, but the fact that he lies is one thing; the fact that she goes alog with it in order to save his pride is another. Linda enables him rather than helps him.
2) Willy becomes angry with Linda when she's mending stocking because, he's reminded of when he gave stockings to the "Other Woman" and Biff asked why he was giving away mom's stockings. Willy wants to start new and not have stuff mended. He wants to give Linda new stockings, so he's not reminded of the past. This is important because we get a glimpse into the Willy who wants to KEEP what he has; he doesn't want to lose his wife, but yet he doesn't want to fess up to his mistakes.