The article provides the context that people will sometimes make things up about celebrities when they're in the news, then gives an example of when it has happened before.
It's less feasible to prove a negative, "prove that she didn't do x". I can't provide an article about this specific claim because it never happened outside of this block of text. Aside from that, why wouldn't the hospital still bill insurance, then Dolly cover the rest. Thats just bad finance.