The phrase "They had done her hair and she was spotless" comes from the Cambridge Corpus, which is not quite the same as being from the Cambridge dictionary. The Corpus gathers millions of samples of language from sources around the world, and not all these examples are typical of how the language is really used. Some may be non-standard, and all are quoted out of context. We would not normally use 'spotless' to describe a person's appearance. A person's clothes might be spotless (immaculate = literally without any stains or dirty marks) or their reputation can be spotless (without a blemish in a moral sense). But people themselves? Not really. The only context where this could make sense might be when describing a small child who always gets dirty. You might brush her hair, scrub her clean, and then five minutes later the child is filthy again. 'Spotless' could work in this context, but it is far from normal.

Thank you, everybody ;)

Agreeing with everybody barring an exception: Spot-free sometimes could be conflated with Spotless as having clear skin. " Healing from his acne, he had remained spotless for a month now. " " They had done her hair and she was spotless. " Too pretty to be touched, more like an idealistic poetic exaggeration. " I have written a wicked book, and feel spotless as the lamb. " Inarguably it requires some upholding context. Could also generally mean, ' morally unblemished. ' Spotless, the book about a hitman by Camilla Monk https://www.amazon.com/Spotless-Book-1-Camilla-Monk-ebook/dp/B01FR7D4M6 Thanks : )

I agree with everyone, but also you can describe someone as having a '"spotless reputation" or a "spotless driving record."

If you were to talk about a person in the context of there being absolutely nothing wrong with them, "flawless" would be much more suitable. For example, you could look at someone in awe and say "Valeria is beautiful, she has the best grades in school, a perfect family, and a promising future. It's like she's flawless." I hope this helps. Otherwise, I agree with Saorla. "Spotless" is used as the highest standard of cleanliness. but only for rooms and inanimate objects.