Her best friend could be another main character. They might have a conversation about whether getting a tattoo is a good idea or not. The friend could either encourage Ginny or try to talk her out of it. And if the friend has tattoos already, they could share their own experiences.
There could be the tattoo artist. He or she might be an interesting character with a lot of stories about the tattoos they've done in the past. They could have a unique personality and play an important role in guiding Ginny through the process.
It could be about Ginny's journey to get a tattoo. Maybe she has a specific design in mind that has a deep personal meaning, like a symbol representing her family or a memorable event in her life.
Hermione could be a main character. She would use her vast knowledge of magic to try and find a cure or treatment for Ginny's injury. Luna Lovegood could also be important. She might have some unique insights or magical remedies that could help Ginny. And of course, Ginny's parents, Arthur and Molly Weasley, would be main characters. They would be extremely worried and do everything in their power to take care of their daughter.
Obviously, Ginny is one of the main characters. Since the title is about her getting 'the talk'.
The author could focus on Ron as well. Since he's Harry's best friend and Ginny's brother, his reactions to their first meeting could be interesting. Maybe he's a bit overprotective of Ginny at first.
Ginny herself is the central figure. There might also be a character who represents a glimmer of hope for Ginny, like an abolitionist who secretly tries to free the slaves. Even if they don't succeed immediately, they are an important character in the story as they give Ginny some sense of possibility for a different future.
Maybe it's a group of rogue Death Eaters who are still loyal to Voldemort's ideals. They believe that by kidnapping Ginny, they can disrupt the peace in the wizarding world and send a message to those who defeated Voldemort.
Neville could be another important character. He could be like a godfather to their children, teaching them about Herbology and sharing his own experiences of growing up in the wizarding world. Luna could also be involved. She might bring some of her unique and dreamy ideas to the family, like introducing the children to some strange but fascinating magical creatures she discovered. And of course, the Weasley family as a whole would be very much present, with Molly Weasley spoiling the children with her delicious magical cooking.
It could be a long - time boyfriend that we haven't known much about in the original story. Maybe he's a character who was in the background but now becomes central to the plot.
Obviously Ginny would be one of the main characters since she's the one who faints and is pregnant. Harry could also be a main character as he might be her partner or husband, and he would be involved in the story, supporting Ginny through the pregnancy.
It could be a rival from another house. For example, a jealous Slytherin who wants to take Ginny out of the Quidditch game. They might use some underhanded tactics to make her broom malfunction and cause her to get hurt.