I think the likelihood is that she was sent to Taiwan as a warning to China. American intelligence probably told Biden that China was going to invade Taiwan, and this was America's 'discreet' warning.

I say that because the Washington Post ran an excellent post that when American Intelligence knew that Russia was going to invade Ukraine (6 months before), they sent countless diplomats to Ukraine, EU, and Russia. Russia denied it, and the rest didn't believe it.

Why not? America lied to the international community about Iraq and forced numerous countries into a useless war, and the international community has never forgiven America.