Yes, it's possible. Fanfiction writers often create different versions of relationships. Some may write about Thor and Jane's relationship from a platonic love angle that can be suitable for all audiences. They could write about their shared adventures and how they grow together as friends who care deeply for one another.
There might be some fanfictions that focus on their relationship in a more innocent and family - friendly way. For example, some could depict their emotional connection, like how they support each other during battles or in difficult times. They might share tender moments like having deep conversations under the stars, without any inappropriate content.