Taylor Swift lets the company that manages the jet (that she owns? that she leases? I have no clue) so it looks like it's all her but it's just under her name I think. I could be wrong.
Carbon Neutral is bullshit. Unless they are actually sequestering gasses from the atmosphere, and they don't do it. What they are doing is buying "carbon credits" (according to their own website), which means - "someone else will be responsible for my own emissions".
Running one of the worst possible businesses for emissions (vanity air travel) and having the gall to call it sustainable is rather jarring.
And if they're not actually carbon neutral than the leasing company is committing fraud, not say, Taylor Swift.