Hi. I'm Dr. Lee and will do my best to help.
What you are seeing is likely a healing dermatitis (skin infection), which often times will make the skin discolor or becomes darker. Since it's not bothering her, there is nothing you need to do. The more you messed with it, the higher the chance it will get irritated. I would suggest to monitor the skin and look for any additional scabs and also any itching. If itching occurs, you need to immediately start giving Benadryl at 1 mg per pound of body weight every 12 hours, to prevent the itching from becoming a bad ski infection.
Please let me know if you have any questions or concerns. Thanks.
Since she is not bothering it, there is no real need to use anything. However, if you want to, you can clean the area with hydrogen peroxide every 12 hours, as well as apply neosporin on it every 12 hours. This might help the healing process a little bit.