My daughter just had a "freckle" removed from her scalp. What type is this? Is cancer in an 8 year old common? (photo)

We live in AZ. It is rather small and there was no color underneath where they removed it. She has had it several years and it hasn't noticeably changed, grown at all. However the dermatologist said the edges weren't as sharp as they should be and it was multi colored. She has freckles elsewhere of no concern, blue eyes and her grandfather had some of the edge his ear removed around age 70 for skin cancer.