She is British (it says so on her site). Using plural verbs with organizations ("the police are coming", etc.) is perfectly correct British English; same for "at university" [1].
I'm not a native speaker, and learned British English in school, American English through informal practice while living there, so I may not have picked the greatest example. :)
I think it is. I don't know the rules, but I've never heard a US English speaker use an entity like "Disney" as plural. That said, "the police" is always plural, and I have no idea why that's different.
It's not correct American English, but she's not American.
The only thing I'm not sure is correct in non-American usage is the capitalized "University"; I thought they used lowercase for the generic (much in the same way we use "college" in the US). The rest, though, reflects common usage outside the US.
Disney have used it..."
If she passed any English classes or graduated from the mentioned university, then she deserves a tuition refund.