As mentioned above, airport and airlines are heavily subsidized, this includes private airports and jets. For a limo, taxes pay for the road - but everyone can drive on it, so it'd exist with or without them. Maybe a better comparison would be if she had a bus that she travelled in alone, compared to the average person that'd be equally ridiculous.
The emissions of a limo is pretty much in line with the emissions of a family car. Most people wouldn't have a small car and a family car for when they're alone, so even if someone is alone on a limo, they're probably not doing much more harm than the average person.
A private jet's emissions are significantly more per passenger than a commercial plane. Even if a private jet always flies at max capacity - which I'd bet rarely happens - it'll cause significantly more emissions per person than a commercial plane (it's difficult to link a source here as I've not found an exact number. The estimates I've found range between 10 to 43x. Even assuming just 10x that's quite a difference)