Some fanfictions could be about Chichi's past. What was her life like before she met Goku? How did she become such a strong - willed woman? These types of fanfictions can provide a lot of background and depth to her character that we might not have seen fully in the original 'Dragon Ball Z' series.
One common theme is family. Given their roles as husband and wife and as parents, a lot of fanfiction explores how they balance family life with the constant threats in the Dragon Ball Z world. For example, stories might show Goku trying to be a better father while still being the planet's defender.
One interesting storyline could be Goten getting into trouble at school and Chichi trying to discipline him in her own unique way. Maybe he used his Saiyan powers accidentally and she has to teach him about hiding his true nature among humans.
You can start by looking on fanfiction websites such as FanFiction.net or Archive of Our Own (AO3). Just type in 'Dragon Ball Z Chichi' in the search bar, and a bunch of relevant fanfictions should pop up.
They could go through a period of misunderstanding. Maybe Gohan makes a decision about his future that Chichi doesn't initially understand. Through communication and some trials, they grow closer as they learn more about each other's perspectives.
One great piece of fanfiction could be 'Chichi's Training Regimen for Goku'. In it, Chichi decides to take Goku's training into her own hands to make sure he's not just focused on fighting but also on family. It shows a different side of their relationship, with Chichi being more assertive in Goku's life.
One way is to put them in a difficult situation together. Say they are stranded on an alien planet. Chichi would have to rely on Goten's Saiyan powers to survive and Goten would have to listen to Chichi's wisdom. This would force them to understand each other better and strengthen their bond.
A plot could revolve around Chichi wanting Gohan to focus more on his studies and less on training. This causes some tension between them as Gohan feels he needs to train to protect his family. It could show how they resolve this difference in priorities.
There are no such inappropriate 'Straight Shota' stories in the official Dragon Ball Z canon. Dragon Ball Z mainly focuses on epic battles, power-ups, and the adventures of Goku and his friends to protect the Earth from various villains.