There might be such a fanfic. The 'Steven Universe' fandom is quite large and creative. However, it's also possible that it doesn't exist. You could try searching on popular fanfic websites like Archive of Our Own or FanFiction.net to see if there's a story with this concept.
Adventure is also a common theme. They go on different quests or face various threats together. This could be something like exploring an ancient gem ruin on Earth or fighting off a new enemy. The theme of acceptance is important too. Accepting each other's flaws and differences. Amethyst accepting Steven's sometimes naive view of the world, and Steven accepting Amethyst's wilder side.
Well, it could be about the unique relationship between Pearl and Amethyst being extended to their gemlings. Maybe it shows how they raise the gemlings together, teaching them different things based on their own skills and experiences. For example, Pearl might teach the gemlings about grace and precision, while Amethyst could show them how to be more in tune with their wilder sides.
Friendship and family are also likely themes. In the Steven Universe world, relationships are important. The fanfics might show how the relationships between Pearl, Amethyst, and their gemlings form a sort of family unit or a strong friendship bond, dealing with the joys and challenges that come with it.
One possible theme could be discovery. As I said before, if the lemon is some sort of new or magical object, the characters are on a journey of discovery about it. Another theme could be acceptance. If 'lemon' is a new character or concept, the other characters have to learn to accept it. For example, Amethyst might be more open - minded while others like Garnet or Pearl might be more skeptical at first.
A 'Steven Universe Amethyst Pregnant' fanfic could be a story that delves into the origin of the pregnancy. Is it some sort of magical or scientific anomaly? How does Amethyst feel about becoming a mother? She has always been the more carefree and fun - loving gem among the Crystal Gems. This new situation could force her to grow up in a way. It could also touch on the theme of family and what it means to create a new life within the context of the unique world of 'Steven Universe', exploring how the different species and cultures in the show interact with this unexpected event.
I'm not sure of specific 'Pearl x Amethyst Gemlings' fanfics off the top of my head. But you could also check out Archive of Our Own (AO3). It has a large collection of fan works. Use relevant tags to narrow down your search for the ones related to this pairing and the gemlings.
In Steven Universe fanfiction, the relationship between Steven and Amethyst can be really interesting. They are both very different characters. Steven is kind - hearted and has a strong sense of justice, while Amethyst is more of a free - spirited and somewhat rebellious character. In some fanfictions, their relationship might develop into a deep friendship where they support each other through different challenges. For example, Steven could help Amethyst come to terms with her insecurities about being a 'lesser' gem compared to the others.
It could be about a unique adventure. Maybe Amethyst discovers a lemon - shaped magical object and she and Steven go on a journey to figure out its power. Since Amethyst is known for her wild and carefree nature, she might get into some comical situations while exploring the mystery of this lemon - related item with Steven.
Well, one aspect could be the unique relationship between Peridot and Steven in the fanfic. Peridot is such an interesting character with her growth and development throughout the series, and when paired with Steven, there can be many new storylines. Maybe it focuses on their friendship deepening into something more, or perhaps it's about them going on adventures together that are different from the main plot of the show.