One possible plotline could be her journey in a magical world filled with other mythical creatures. As a female Jack Frost who is also a Pooka, she might struggle to fit in or find her place among the different magical beings.
Maybe she has a special mission. Since she is both Jack Frost and a Pooka, she could be tasked with bringing balance to the seasons and the magic of the Pooka world. She might face challenges from those who don't believe in her ability to do so, or from dark forces that want to disrupt the balance. For example, she could have to battle against an evil wizard who wants to control the seasons for his own gain and at the same time, deal with the politics within the Pooka community.
Another plotline could involve her relationships. She could form an unlikely friendship with a human who discovers her secret. This friendship might be complicated as she has to hide her true nature from the rest of the human world. Or she could fall in love with another mythical being, perhaps a fire - based creature, creating a story of star - crossed lovers as their natures are so different. Her story could also be about self - discovery, as she figures out how to use her combined powers of Jack Frost and a Pooka to her fullest potential.
Perhaps in this form, Jack Frost is befriended by a young human child. The child doesn't realize he's Jack Frost and just thinks he's a really cool and strange little animal. They go on adventures together in the winter wonderland, with Jack Frost using his powers in small, unnoticeable ways at first.
One common theme is friendship. Since they are two different characters from similar mythological - inspired backgrounds, their journey to become friends is often explored. For example, they might start off as strangers but gradually learn to understand and support each other.
I'm not sure about specific 'Jack Frost is a female Pooka' fanfiction, but you can try searching on fanfiction websites like Archive of Our Own. They usually have a wide variety of fan - made stories based on different concepts.
One interesting story could be about Jack Frost teaching Baby Pooka how to create unique ice sculptures. In this fanfiction, Jack Frost uses his powers over ice and snow to show Baby Pooka the beauty of his creations. Another could be a story where they team up to save their magical realm from an encroaching darkness. They use their individual abilities, Jack's cold powers and Baby Pooka's special skills, to fight off the evil forces.
A great fem Jack Frost Pooka fanfiction that I've come across is 'Fem Jack's Encounter with Pooka'. This fanfic delves deep into the first meeting of the two. The fem Jack Frost is initially wary of the Pooka, but as the story progresses, they learn to trust and rely on each other, all while set against a backdrop of a frozen, enchanted forest.
A possible plotline could be that Jack Frost is on a mission in Rapunzel's world and accidentally stumbles upon her tower. They form an instant connection. As their relationship progresses, Rapunzel gets pregnant. Now, they need to figure out how to raise the child. Jack Frost wants to introduce the child to his icy world, but Rapunzel is worried about the cold environment. Meanwhile, there could be a villain, like an evil witch or a jealous magical being, who wants to harm Rapunzel and the baby. So they have to rely on their combined powers and the help of their friends from both their worlds to protect their family - to - be.
The plot could center around Jack Frost being cursed into his baby pooka form by a mischievous winter spirit. He then has to find a way to break the curse. Along the way, he meets other magical beings who either help or hinder him. For example, a snowman he created in his normal form might come to life and guide him to a magical crystal that has the power to reverse the curse.
One possible plotline could be that Jack Frost discovers something strange related to Pitch, like a 'lemon' - themed object that has some sort of power over Pitch. And he has to figure out how to use it to either defeat Pitch or make him change his ways.
You can start by looking on popular fanfiction websites such as Archive of Our Own (AO3). It has a wide variety of fan - created content, and you can search specifically for Jack Frost and Baby Pooka stories using the search function. Another option is FanFiction.net, which also has a large collection of fanfiction, though the tagging system might be a bit different.
One possible plotline could be that Hiccup and Jack Frost meet when a strange magical event causes their worlds to collide. They then have to work together to find a way to separate the worlds again while also dealing with the local problems in each other's worlds, like Hiccup helping Jack with some mischievous spirits in Jack's world.