I'm not sure of a specific fanfiction with this exact plot, but you could try searching on fanfiction platforms like Archive of Our Own. Use tags like 'Bellatrix Lestrange', 'daughter', and 'pregnancy' to narrow down your search. There are often many creative interpretations in the fanfiction community that could explore this interesting concept.
There might be a fanfic titled 'A New Beginning for Bellatrix's Daughter'. In this, her pregnancy could be a symbol of hope in a rather dark and chaotic wizarding world. It could show her journey of self - discovery as she becomes a mother, breaking away from the shadow of her infamous mother.
A major plot twist could be that the father of the child is a secret enemy spy. This would add a whole new layer of drama as Bellatrix's daughter has to deal with the betrayal and also protect her child from both sides. Another could be that the pregnancy is part of a magical prophecy that she was unaware of, and it has far - reaching consequences for the wizarding world.
One great Bellatrix Black and Rodolphus Lestrange fanfiction is 'The Dark Bond'. It delves deep into their relationship within the dark wizarding world. It shows how their loyalty to Voldemort intertwined with their relationship to each other. The story is full of dark magic elements and complex character interactions.
There's a fanfiction that delves into their backstories. It shows how they were both part of the Black family but took such different paths. Sirius, with his more progressive views, and Bellatrix, with her dark and twisted loyalty to Voldemort. The story might have some interesting flashbacks and interactions that are both poignant and full of conflict.
There's a fanfic where Bellatrix Lestrange's son is sent away as a baby to protect him from the chaos of the wizarding war. He grows up in a different magical community, unaware of his true heritage at first. As he gets older, he starts to have strange dreams and visions that lead him back to the wizarding world he was born into, and he has to face the truth about his mother.
There's also 'Twisted Fates'. This fanfiction plays with the idea of fate and how Sirius Black and Bellatrix Lestrange could have had a different kind of connection. It's a very creative piece that takes liberties with the characters but still stays true to their core traits. The story is full of unexpected twists and turns that keep you hooked from start to finish.
One possibility could be Rodolphus Lestrange, her husband in the wizarding world. It would be a traditional choice and could explore how their relationship evolves during the pregnancy. Another option could be Voldemort himself. It would be a very dark and twisted scenario, but it would add a lot of drama to the story.
One great 'OC Son of Bellatrix Lestrange' fanfiction is 'The Heir of Chaos'. It explores the life of the OC as he struggles with his mother's dark legacy. The author does a wonderful job of creating a believable world within the wizarding universe. The character development is really engaging, as the OC tries to find his own path, different from the pure evil associated with Bellatrix.
One great Severus Snape x Bellatrix Lestrange fanfiction is 'The Unlikely Bond'. It explores a scenario where they are forced to work together on a secret mission for Voldemort. Their initial hatred for each other gradually turns into an unexpected understanding. Another interesting one is 'Shadows of the Dark'. In this story, it delves into their pasts and how certain events in their youth might have led to a different kind of relationship than what was expected.
One great Bellatrix Lestrange x Male OC fanfiction is 'The Dark Bond'. It explores a unique relationship where the Male OC has a complex past that intersects with Bellatrix's loyalty to Voldemort. The story is full of tension and mystery.
Fanfiction often takes creative liberties. So, the relationship between Bellatrix Lestrange's daughter and Hermione could be full of twists and turns. For instance, the daughter could be a double agent, pretending to be on the dark side but actually helping Hermione and her friends. This could add a layer of mystery and intrigue to the story. Hermione's character, with her quick thinking and determination, would play a crucial role in this complex relationship, either trusting or being skeptical of the daughter's true motives.