Mrs. Ali is the local shopkeeper in Edgecombe St. Mary. As we learn from the awful graffiti on her shop wall—"Pakis go home!" (1.24)—she's of Pakistani descent, though she was born and raised in England. She's about ten years younger than the Major, and her husband, Ahmed, recently died of a heart attack. When he died, he "broke with family tradition" (1.102) to leave her the shop.
Breaking with tradition is a habit of Mrs. Ali's. Pretty much everything she does is against the grain. She's the only Pakistani in a village full of stodgy old white British folks. She's a woman who owns a shop and drives, much to the chagrin of her nephew, Abdul Wahid. She likes Rudyard Kipling, a notorious imperialist. And she enters into an interracial relationship with the Major, a mostly traditional man who, on the surface, is everything she isn't. But underneath, these opposites attract.
Besides knocking boots with the Major, which doesn't happen until the book's climax (pun totally intended), Mrs. Ali's main goal is to reunite her family, specifically her nephew Abdul Wahid with Amina, the mother of his son. Unfortunately, there are some class issues to contend with here. Mrs. Ali tolerates the racism from the people of Edgecombe St. Mary, but she has no way to rebel against the classism within her own family.
We see a few instances of this class discrimination within the Pakistani community in the book.
Because of class and customs, the Major only knows Mrs. Ali as "Mrs. Ali" until he overhears her first name—Jasmina—in a conversation with her peers… and even then he finds it rude that Saadia Khan doesn't address her as "Mrs. Ali." Saadia, a doctor's wife, refers to Mrs. Ali as "Jasmina" because Mrs. Ali is a shopkeeper, so Saadia feels entitled to be overly familiar with her.
Amina's family will only let their daughter marry Abdul Wahid if Mrs. Ali bequeaths him the shop. That means she would lose her independence, and she isn't willing to do that... until, unfortunately, the racism of the town gets to be too much, and she washes her hands of them all, giving Abdul Wahid the shop and leaving in a small room with her brother-in-law, Dawid.
Her family takes away her independence more than she ever expected, though. Dawid hides her correspondence, preventing her from communicating with the Major. When the Major gets her address from Grace, he actually swoops in and rescues her from her family, like a prince saving a princess from a tower, and the two are married.
This marriage is just one more example of Mrs. Ali breaking tradition. It's an interracial and interfaith marriage. That's a lot of inters for the sleepy village of Edgecombe St. Mary.
Why is Mrs. Ali such a rule-breaker? We think it's a combination of two factors. First, she never saw herself as an outsider, despite the way she's always been treated. She may have had Pakistani parents, but she herself is a British citizen, born and raised in England. She's never even been to Pakistan. So on the one hand, she's not breaking any rules. She's just as British as the rest of them, and she's definitely more British than the white American characters the villagers have no problem welcoming to town.
The other factor is simply that Mrs. Ali couldn't care less about the opinions of the villagers. They either treat her like she's invisible or like she's a servant. She's neither. And she can prove it by rebelling and making her presence known. Making everyone else uncomfortable is a bonus. British imperialism originally subjugated people and took away their voices. But now many of those people are citizens and equals. Mrs. Ali wants to speak up.