Payment is based on exposure. I have Instagram insights that measure how many image views, unique users, and engagement levels. If my photo is being posted on an Instagram with over 500k followers with no mention of me.... that's at least 5000 people who would have visited my profile based on the "shout out" this IG should be giving.
This is what's happening. My ex went from 500-30,000 followers in five months of traveling with me because we did a lot of cross posting. Tagging each other. It worked well. Now, we're split and she's continuing to post photos I've taken of her, without mentioning. Now, these "Repost" IGs are sharing her content, but only mentioning her, because they got the picture from her IG feed.
If you don't think I'm missing much, I had my photo featured on @followmefaraway, which has 500k followers. I woke up with 3000 new followers. Imagine how many profile views I got....
It may be social media, but it needs to be treated the same way any brand should be.
Correct me if I'm wrong.
It sounds to me like you are expecting someone else to promote you, and if so, I don't see what obligates them to do so.
She's using the work you did together to promote herself, but you're not working together anymore, and not being together releases her from the obligation to include you in her promotion efforts.
If you and I made a video of my dog's antics and then we went separate ways, either one of us could use the video any way we wanted and aren't obligated to mention the video's co-creator.
Whatever you produced together can be used by both of you and neither of you needs to acknowledge the other.
I don't know if that's what a copyright court would find, but that's the way it looks to me.