So I had a friend in elementary school that's not my friend anymore. When we were friends, we had this silly dream of writing a book together, but it never really happened. I dont even think she remembers and to be honest, I didn't either until I cleaned out my room and saw our...drafts. Although it was written by a couple of eight year olds, the basic idea is pretty good. The thing is, I don't know if it's like, morally right to write using this idea. I dont know if I'm making a big deal about this and overeacting since she doesn't even think about it or about ever continuing it, but I just don't know. I know that even if I do end up writing about it, it probably won't even get that much attention to become a controversial thing but it really just was not my idea. It was more her story plot than mine. And I know I could just ask her, but I haven't talked to her since like the 8th grade so I kinda don't wanna be super awkward and be like "hey, so its been, like, three years, how's life~? Yeah, anyways, remember that one story we were writing when we were like 8? Yeah, could I actually just steal that storyline and write about it now, almost a decade later, and publish it online just because I want to? Thanks." I mean, I could just not write about because it's not like an alien has a ray gun against my back threatening to destroy the earth if I don't write it....but I really wanna write about it. And publish it, because I like the feed back I get and the compliments I get once in awhile really help boost my self-esteem (i know this reasoning is hella selfish). Now that I'm writing this though, I'm probably gonna write it nonetheless but I guess the issue is more on the matter of publishing it. I don't know, it's just getting to me. I just like being really careful with intellectual property because I really want to respect the owners. I even make my own covers for my books despite the my horibble art skills because I want to make sure I'm not accidentally using stolen art. Anyways, I just need some other opinions beside my own because I'm hella bias.
Yes, and try to credit her in your writing. I mean indirectly if you still feel awkward about it. Also, try communicate with her once your writing gets really good or at least just nice. It's better to show something that can be shown rather than just speaking it out loud. PS: at least once you have readers for your novel, you can have something to talk about with her to build up the long forgotten friendship
If you are at the point where you are "not friends" any more, you don't really need her permission since it was a co-op work in the first place that was 10 years old. Just remember to credit her help as a "co-author" and you should be fine. Hell, even calling her a co-author is overselling it since it was just a "co-concept designer".
Worry about it when you get there. There's a strong chance you'll have other ideas while writing that'll change it enough that there's no reason to worry about copying or stealing.
I think that you are just missing her and the story kind of reminds you of her, if you want to write the story you can ask her or you can simply just change it if you are adamant on writing it
Write it. It doesn't matter how many years it has passed. If it' a good idea and you want people to know about it. Write it. In terms of IP, I don't think your former/old friend is gonna raising hell for not being credited as a co-author. If you want, you can reach out and ask. If nothing happens, you can always mention her in the dedication like a toast to your old times together.