"Yes, quite an extended family." He detected a dryness in her tone. "But it is not the same as the infinite bond between a husband and wife." (1.30)
Mrs. Ali was closer to her husband than she was to any members of her family, aside, perhaps, from her deceased father, whom she loved and respected very much.
"I have an old tweed jacket that my husband used to wear," she said softly. "Sometimes I put it on and take a walk around my garden. And sometimes I put his pipe in my mouth to taste the bitterness of his tobacco." (1.34)
Losing a spouse is hard, and Mrs. Ali and the Major show that losing a beloved husband or wife isn't something a person ever really gets over. They try to hang on to their spouses as much as possible while continuing to live in the moment.
The will made no mention of any bequests of personal items, to anyone, offering only a single line: "My wife may dispose of any and all personal effects as she deems fit." (4.59)
There's a downside to being closer to a spouse than the rest of the family, but that downside is for the family. The Major respects his family, but his brother put his wife and his newer family first.
"My nephew insists he cannot sleep under my roof with an unmarried woman, so he slept in the car," said Mrs. Ali. "I pointed out the obvious inconsistency in his thinking, but his new religiosity permits him to be stubborn." (12.82)
Abdul Wahid's devotion to his marriage has him pretending that he can't be in the presence of an unmarried woman. The "obvious inconsistency" here is that this didn't stop him before: he is the father of Amina's child, meaning that he did more than just sleep under a roof with her.
"We have no plans to get married anytime soon, or I would have told you." (13.90)
The Major is a traditional man. He's not as traditional as Abdul Wahid, but he still values marriage, and it seems like he'd rather Roger and Sandy be married if they're going to live together.
"Marriage is a wonderful part of life," said the Major.
"Yes, so's retirement," said Roger. "But you might as well put them both off as long as possible." […]
"All this lack of commitment these days—doesn't it smack of weakness of character?" (13.94-13.96)
The Pettigrew family's attitudes toward marriage are very representative of modern attitudes. Many younger people, like Roger, don't see marriage as the same commitment as their elders do.
"They took me away from her because of faith. I didn't like it, but I understood and I forgave them. Now I fear they withdraw their objection in order to secure financial advantage." (14.106)
In Abdul Wahid's culture, marriage isn't about love—it's about a transaction. Abdul Wahid doesn't approve of this. He doesn't want to marry Amina just so his family can gain a store.
"What about the wedding?" [Mrs. Ali] asked. "I must see them safely married." (21.81)
Just because Mrs. Ali thinks it's silly for Abdul Wahid to refuse to sleep in a house with an unmarried woman, that doesn't mean she's not excited to see him get hitched. She makes attending the wedding her top priority… even if it ends up not happening in the end.
"Must ask you to marry me," he said as he drifted away. "Not in this dreadful room, of course." (25.60)
The Major isn't going to waste any time marrying Mrs. Ali. They don't have much time left, after all, so he doesn't have the luxury of waiting the way Roger thinks he does.
"Mrs. Ali," he said, delighting in using her name one last time, "shall we go forth and get married?" (Epilogue.15)
This is the final line in the book. Perhaps Major Pettigrew's last stand is him standing next to Mrs. Ali at the altar?