Her tail is going dark, it was like this when I got her and it's slowly crawling upwards on her tail. I've tried soaking her in a bath, putting oils on it and using a toothbrush to rub off any stuck sheds that may be causing it but nothing worked. Please help.
I don't see any tail damage in those photos. It looks like a natural darkening as you move toward the tip of the tail which is common. The end of the tail looks a bit grayer than the rest of her body so there may be a tail shed coming on soon. I don't see anything that would cause me concern.