One common theme could be the secrecy of their relationship. Given their positions or the context they are in, they might have to keep their love hidden. Another theme could be the power dynamics, especially if one of them has a more powerful or authoritative position.
There are likely many 'albus and minerva love' fanfictions out there. One way to find them is to join relevant fan communities on platforms like Reddit. For example, there might be a subreddit dedicated to the fandom of the world they are from. There, fellow fans can recommend some really good fanfiction pieces about their relationship.
The main characters are obviously Albus and Minerva. Albus Dumbledore is often portrayed as a wise and powerful wizard, and Minerva McGonagall is known for her strict yet fair nature. In the fanfiction with a baby involved, they are likely to be the caregivers or parents of the baby, so the baby would also be a significant character, though perhaps more of a focal point for their actions and decisions.
In fanfic, Albus is often portrayed as the wise and somewhat mysterious figure. He has a deep understanding of magic and the wizarding world. Minerva, on the other hand, is depicted as strong - willed and highly intelligent. She is very protective of Hogwarts. Their relationship in fanfic usually involves a mutual respect and a certain level of unspoken understanding.
One problem is that it distorts the original relationship between the two characters. In the source material, their bond is more about friendship and mutual understanding, not a romantic or sexual one.
One plot idea could be a story set in an alternate universe where Minerva and Albus got married in their youth. They could face challenges from the wizarding society that disapproves of their union due to their positions at Hogwarts. For example, some might think it would create a conflict of interest. Another idea is a time - travel fanfic where they get married in a different era and have to adapt to the different cultural and magical norms of that time.
One great friendship story could be where they work together to solve a mystery within Hogwarts. They combine their wisdom and experience, Albus with his deep knowledge of magic and Minerva with her strict yet fair approach. They might start by suspecting a group of mischievous students but then discover it's a more complex issue involving a hidden magical artifact that's causing strange occurrences in the school.
In some Albus and Minerva baby fanfiction, the plot could revolve around the baby being a key to uniting different magical communities. Albus and Minerva find themselves in the middle of this, having to raise the baby in a way that will make it able to fulfill this great destiny. They might face challenges like teaching the baby different magics from different cultures and dealing with jealousies or rivalries from other wizards who don't want this unity to happen.
You can try fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions on various topics, including those related to Albus and Minerva. Just use the search bar and type in relevant keywords like 'Albus and Minerva pregnant' and you should get a list of available stories.
One great fanfiction could be 'The Miracle of Albus and Minerva'. It might explore how their relationship changes with the news of pregnancy, delving into their emotions and the reactions of the wizarding community. Another could be 'A New Chapter for Albus and Minerva' which focuses on their preparations for the new arrival while also dealing with their duties at Hogwarts.