I'm aware. Assume copyright. That's the industry standard. Much of that exists to protect the work of the starving artist, so they don't have to lawyer up and fight corporate thieves.
You're right about providing sources. I can't argue this. Getting permission from the original creator is sometimes as easy as sending an email, if that's a requirement. She failed to follow standard practices.
This artform is welcome here but it does come with a lot of loose ends that need to be tied up before it can be published. It would be wrong to give some artists special treatment and let a few things slide. Fairness in a world that seems so unfair, right?