It could be Flynn Rider. Since they have a strong relationship in the original story, it's very likely that he is the father. They are in love and have been through a lot together, so it would make sense for him to be the one.
One interesting fanfiction could be where Jack Frost accidentally freezes Rapunzel's long hair and then has to find a way to thaw it without causing her harm. Another might be a story where they meet in a magical forest during a solstice event and team up to defeat an evil sorcerer who is threatening both their worlds.
Well, the plot could involve Rapunzel seeking advice from her fairy - godmother - like figure. She could be worried about passing on her long - haired trait to the baby. There could also be a sub - plot where the villain from the original story tries to take advantage of her vulnerable state during pregnancy. But Rapunzel, with her strong will, overcomes these challenges.
In a 'Rapunzel pregnant fanfiction', Flynn would likely become more responsible. Rapunzel's pregnancy would be a big change for him. He might start to take on more tasks, like building a proper home for them. Their relationship would also have more emotional depth. Rapunzel would rely on Flynn more, and Flynn would feel a stronger sense of duty towards her. They would have to communicate more about their hopes and fears for the baby and their future.
Fanfiction.net is also a great place to search. It has been around for a long time and has a vast number of user - generated stories. Just type in 'Jack Frost and Rapunzel' in the search bar and you'll get a list of relevant fanfictions. However, the quality may vary, so you might need to read a few summaries or reviews if available to find the good ones.
For a 'Rapunzel pregnant fanfiction', consider this. Rapunzel and Flynn are traveling when she starts showing signs of pregnancy. They stop in a small village where the people are not very accepting of a pregnant unmarried woman at first. Rapunzel has to use her charm and kindness to win them over. Meanwhile, she has strange dreams about the baby's future. Is the baby going to inherit her long hair? Or will it have some other magical ability? She spends her days making a safe and warm place for the baby to be born while Flynn goes out to gather supplies and ensure their safety.
Well, I've come across some. Some fanfics focus on how Jack Frost, with his icy powers, and Rapunzel, with her long hair, meet in a magical forest. Their different natures create an interesting dynamic. In these stories, they often have to overcome obstacles like an evil sorcerer who wants to keep them apart to fully embrace their love.
Well, it's possible that such a fanfiction exists. Elsa and Jack Frost are from different fictional universes (Elsa from Frozen and Jack Frost from Rise of the Guardians), but in the world of fanfiction, people often cross over characters and create all kinds of scenarios. However, I haven't personally come across a 'pregnant' fanfiction involving them. You might have to search on some dedicated fanfiction websites to find out for sure.
In this fanfiction, perhaps Kate initially hides her pregnancy from Jack because she's afraid of how he'll react. But as time goes on, she starts to show signs that are hard to conceal. Jack finally figures it out when he catches her having a bout of morning sickness. He is initially shocked but then becomes very protective. They then have to face the reactions of the other survivors, some of whom are supportive while others are worried about the added burden.
Well, it's hard to say it's a popular genre across all fanfiction. In some smaller, dedicated fandoms related to the characters Jack and Ashi, it could potentially be a somewhat popular concept for fanfiction. However, compared to more common fanfiction themes like adventure or romance in general, it's likely not as widespread. It really depends on the size and enthusiasm of the specific fanbase for Jack and Ashi.