The Kardashians might have a lot of possessions, but they’re not possessive. The plural is Kardashians, without an apostrophe. Please ignore what you read on Yahoo! Beauty:
How many errors can be squeezed into a single sentence? If it’s on Yahoo! Style, at least four, each of which is completely avoidable:
If you’re writing about people, the preferred pronoun is who or whom, not which. There’s an apostrophe missing in what should be brand’s. And of course there are two misspelled names: Missy Elliott and Cara Delevingne.
This doesn’t represent one day’s worth of errors; it just represents a single error in a single caption on Yahoo! Style:
This is what the Associated Press calls a quasi possessive. If you’re as confused about whether it requires an apostrophe, I have a little trick you can use so you don’t embarrass yourself in public.