Monica Wilkins is the false identity created for Mrs. Granger, the Muggle mother of Hermione Granger. This alias was the result of a powerful Memory Charm cast by Hermione in 1997 to protect her parents from Lord Voldemort and his Death Eaters during the Second Wizarding War. Under this new identity, she and her husband, who was given the alias Wendell Wilkins, were made to believe their lifelong ambition was to move to Australia, which they promptly did, remaining ignorant of the magical conflict and their daughter's peril.
Mrs. Granger lived with her husband, Mr. Granger, in England. Both were practicing dentists and were loving and supportive parents to their only daughter, Hermione. Though initially bewildered by the revelation that Hermione was a witch, they embraced the Wizarding world and were demonstrably proud of her exceptional academic achievements at Hogwarts School of Witchcraft and Wizardry. They accompanied Hermione to Diagon Alley for her school shopping, where they exchanged Muggle money for Wizarding currency at Gringotts Wizarding Bank and met Harry Potter and the Weasley family. They were sensible, organized, and cared deeply for their daughter's well-being.
In the summer of 1997, as Lord Voldemort's power grew and the Ministry of Magic fell, Hermione knew her parents would become targets due to her close friendship with Harry Potter. To save their lives, she made the heart-wrenching decision to erase herself from their memories. She modified their memories to make them believe they were Monica and Wendell Wilkins, a childless couple whose greatest desire was to emigrate to Australia. This highly advanced piece of magic ensured they would be far away and safe from the war. Immediately after the charm took effect, they sold their house and left the country. Hermione considered this act both a terrible sacrifice and a necessary precaution.
The original novels do not confirm whether Mrs. Granger's memories were ever restored. However, J.K. Rowling has stated that immediately after the end of the Second Wizarding War and the Battle of Hogwarts, Hermione traveled to Australia to find her parents. She successfully located them, reversed the powerful Memory Charm she had placed upon them, and brought them back home to England. (J.K. Rowling interview).
The novels provide no specific physical description of Mrs. Granger. In terms of personality, she was a kind, intelligent, and level-headed woman. She and her husband were very proud of their daughter and adapted to the strangeness of the Wizarding world with practicality, even if they found things like owl post slightly confusing. Her love for Hermione is evident in her support, and this love was fiercely reciprocated by Hermione's extreme measures to protect her.
As a Muggle, Mrs. Granger possessed no magical abilities or skills whatsoever.
Mrs. Granger's possessions were typical of a professional Muggle living in England, including a house and a dental practice, both of which were sold when she and her husband moved to Australia under their false identities. She did not own any known magical objects.
In the film adaptation of Harry Potter and the Deathly Hallows – Part 1, the memory modification is shown on screen. Hermione Granger is depicted casting the Obliviate spell on her parents. As the spell takes effect, her image magically vanishes from all the family photographs in the house, visually representing her being erased from their lives. The film also includes a brief scene of her parents, as Monica and Wendell Wilkins, in Australia. (film).