Perhaps Mary Poppins is a time - traveler in the fanfiction. She travels back in time to the founding of Hogwarts and has a hand in creating some of the magical traditions there. Then, in the present day, she returns to Hogwarts to see how those traditions have evolved. Along the way, she meets Harry Potter and his friends and helps them solve a mystery related to the history of the school. This could involve exploring hidden passages and deciphering ancient spells. Her ability to make the impossible seem possible would be a great asset in this adventure.
A great plot could be that Mary Poppins' magic umbrella is actually a powerful wizarding artifact that has been lost for centuries. When it shows up at Hogwarts, it causes all sorts of chaos as different factions try to get their hands on it. Mary Poppins then has to team up with Harry Potter and his friends to protect it. She could also teach them some new spells and charms along the way. For instance, she might show them how to use the power of song to enhance their magic, like she does in her own world. And her parrot - umbrella handle could have some secret knowledge to share about the history of the wizarding world.
One idea could be that Mary Poppins and Bert go on a magical adventure outside of London. They might discover a hidden land where the laws of nature are different. For example, animals can talk and the trees can move. Another plot could involve them helping a group of lost children find their way home through a series of challenges and magical encounters. Maybe they have to solve riddles set by a mischievous sprite.
One idea could be that the OC is a new neighbor who has a special power related to music. When Mary Poppins returns, the OC's music power somehow interacts with Mary's magic, creating a whole new kind of adventure. For example, their combined powers could bring an old, forgotten carousel in the park to life, and they have to deal with the chaos that ensues as the carousel animals start running wild around the town.
One possible plot could be that Mary Poppins somehow enters the wizarding world of Harry Potter. Maybe she arrives at Hogwarts to teach a special class on manners and propriety, which the Hogwarts students desperately need. She could use her magic umbrella to fly around the castle, much to the amazement of the students. Her unique brand of magic, which is more about making the ordinary extraordinary, could clash or combine with the more traditional spell - casting magic of the wizards.
One idea could be a crossover with 'Alice in Wonderland'. Mary Poppins could find herself in Wonderland, using her magical powers to navigate the strange and topsy - turvy world. Maybe she helps Alice deal with the Queen of Hearts in a more diplomatic way than usual. Another could be a crossover with 'Peter Pan'. Mary Poppins and Peter could team up, with Mary's no - nonsense attitude and magic mixing with Peter's carefree and adventurous spirit. They could fly over London together and have all sorts of adventures.
Perhaps in the fan fiction, Mary Poppins has to deal with a new villain who is trying to steal the magic from London. The children could help her by using their unique skills and the lessons she has taught them. It would be a great adventure with lots of suspense and action.
Magic is a very common theme. Since both 'Harry Potter' and 'Mary Poppins' are set in magical worlds, fanfictions often explore different types of magic. For example, how Mary Poppins' magic of tidying up and her flying umbrella might compare to the spells in 'Harry Potter'.
The plot could start with Harry facing a seemingly insurmountable problem in the wizarding world, like being cornered by a powerful dark wizard. Just when all seems lost, Mary Poppins appears out of nowhere. She might use her magic to confuse the dark wizard and then take Harry away on her flying umbrella.
Yes, you might be able to find such a fanfic on FanFiction.net. But it could take some searching through the various categories and tags.
Well, I found 'The Meeting of Mary Poppins and Harry Potter'. This fanfiction imagines what would happen if Mary Poppins was called upon by Dumbledore to help Harry during a particularly difficult time. It shows how Mary Poppins' no - nonsense attitude and her magical abilities blend with the world of Harry Potter. It has some really heartwarming moments as she tries to understand and assist the young wizard.
One way to blend them creatively could be by having Mary Poppins visit Hogwarts. Maybe she could use her magical nanny skills to teach the students some unique lessons, like how to clean up a potion spill with just a snap of her fingers. She could also interact with the magical creatures there, perhaps taming a hippogriff in her own special way.