Well, she can't lie about everything.

She has a tendency to take the who/what/when/where/why of a story, fluff the details, add a source to make her sound more reliable, and make her own conclusions.

For example, with Hermione she didn't just write a story about Hermione had been convicted of making love potions and was on day release from Azkaban. She took Hermione's very real friendship with Harry and Hermione's very relationship with Krum, and twisted it into a love triangle.

For the Quidditch World Cup, she can't just make up a story about how there were several bodies dragged out after the 1994 Quidditch World Cup or how the rioters killed the family of muggles, because people would call her on it.

"I knew it," said Mr. Weasley heavily. "Ministry blunders… culprits not apprehended… lax security… Dark wizards running unchecked… national disgrace… Who wrote this? Ah… of course… Rita Skeeter." [snip. Mr Weasley starts reading the article aloud.] "If the terrified wizards and witches who waited breathlessly for news at the edge of the wood expected reassurance from the Ministry of Magic, they were sadly disappointed. A Ministry official emerged some time after the appearance of the Dark Mark alleging that nobody had been hurt, but refusing to give any more information. Whether this statement will be enough to quash the rumors that several bodies were removed from the woods an hour later, remains to be seen.'

She made the rumour about the bodies out of whole cloth, but the rest of it is pretty much true. Culprits not apprehended, check. National disgrace, check. Lax security and ministry blunders, check and check. Dark wizards, check. People waiting for news, check. Ministry official saying that no one had been hurt but refusing to give further information, check.

So in the case of this article, she's more likely to fluff things and cast doubt on motivation than she is to twist easily verifiable facts like "Harry and his family attended the quidditch cup and sat in the VIP box and camped in the VIP section."

I don't mean that she's not lying or that she's no terrible, but she tends to have an accuracy rate of like 85%.