One common theme is redemption. Jack has a troubled past, and Shepard often plays a role in helping her find a new path, which leads to their romantic connection. Another theme is the power of acceptance. Shepard accepts Jack for who she is, quirks and all, which is very appealing to Jack.
A major theme is the growth of both characters. Jack learns to trust and love, which is a big step for her. Shepard, on the other hand, might become more in touch with her emotions. Also, there's often a theme of defiance against the norms of their world. Their relationship is not always seen as conventional, but they don't care and pursue it anyway. This gives the fanfictions an element of rebellion and passion.
One common theme could be friendship. Writers might explore how Shepard and Jack Lemon form a unique bond, perhaps through shared experiences or mutual goals.
One common theme is her relationships, like her romantic relationships with other characters in the Mass Effect universe such as Garrus or Kaidan. Another theme is her leadership during difficult missions, showing her strength and decision - making skills.
Love and friendship are very common themes. Since they are comrades in the Mass Effect universe, many fanfictions explore how their initial friendship blossoms into something more. For example, how they support each other during tough battles.
Overcoming differences is also prevalent. Tali being a quarian and Shepard having her own human background, they have to work through various misunderstandings and prejudices. Adventure is another common theme, as they usually embark on exciting missions together in these fanfictions.
One common theme is the power of friendship that turns into love. They start as comrades in arms and gradually develop deeper feelings. Another theme is sacrifice. They are often in situations where they have to make sacrifices for each other or for the greater good of the galaxy.
A less common but still present theme is that of mentorship. Shepard, with her experience and strong moral compass, can sometimes be seen as a mentor to Kasumi, guiding her in making the right decisions in difficult situations. And vice versa, Kasumi can teach Shepard some of her more unorthodox skills.
Overcoming trauma is also a theme. Both characters have their own traumas from their past experiences. Some fanfictions show them helping each other heal. For instance, Shepard might help Thane come to terms with his past actions, while Thane gives Shepard the emotional support she needs in the face of the galaxy - spanning threats she faces.
One common theme is love and romance. Their relationship is often explored in depth, from the initial attraction to deeper emotional connections. Another theme could be adventure. Since they are both part of the Mass Effect universe, fanfictions might incorporate their adventures together, fighting against the Reapers or exploring new planets.
A common theme is the exploration of their complex relationships. Given their distinct personalities, there's always tension and growth. For example, Jack's rough exterior and Miranda's polished demeanor create an interesting dynamic.
One popular fanfiction site is Archive of Our Own. You can search for 'female Shepard Jack romance' there and find a variety of stories. Some might focus on their initial interactions and how their relationship gradually develops over the course of the game's events. Another option could be FanFiction.net, but Archive of Our Own generally has a more organized tagging system for this kind of specific content.