I guess I mean that in this thought experiment it's about waking up as Taylor Swift, not as some random billionaire. Like waking up as Elon Musk seems like it would be a lot more boring than waking up as a talented musician.
When you have as much money as Taylor Swift, you don't need financial knowledge. I struggle to think of how I would spend 1.1 billion dollars. Obviously a really big telescope and the best camera money can buy, but that still leaves me with approximately 1.1 billion dollars to spend
If you're going to stay in her line of business (which you presumably wanted to given the person I responded to wanted her talents) you're going to get bled dry pretty quickly if you don't mind both your finances and who you surround yourself with. Taylor Swift knows what she's doing in both regards.
If you're just going to retire and live off capital gains you'll need less, but you would need to spend some money on security as well, because you're still rich and famous, and a lot of people want a piece of that pie.