In The Thorn Birds, Anne Mueller is a kind, generous, rather passive woman. She suffered from paralysis in her youth, but this pain, rather than embittering her, left her with a sympathetic nature. She is particularly kind to Meggie, and perhaps understands her better than anyone else.
In The Kite Runner, the character who resembles Anne most closely is probably Jamila Taheri. She too has suffered, though from her husband's behavior rather than any physical illness, and is a doting and devoted mother to Soraya. It is difficult to say who is the polar opposite to Anne in this novel. At the beginning of the book, it would be Sanaubar, who is self-centered and unmotherly. However, she mellows later in the novel. The closest character to Anne's polar opposite throughout the novel is Soraya, who is much more assertive and self-willed than Anne, though she is generally a positive character, and is far from unkind.
The closest character to Anne Muellor in A Thousand Splendid Suns is Mariam, who suffers isolation and pain, and who "adopts" Laila and treats her with great kindness, as Anne does with Meggie. The polar opposite of Anne is Mariam's mother, Nana, who also suffers, but whose pain has the opposite effect on her, as she becomes overwhelmed with bitterness, and eventually commits suicide.