The script describes her speech thusly.
[Barbie Alexandra goes into one of those acceptance speecheswomen give, totally self-effacing and not embracing the win.]
BARBIE ALEXANDRA: Oh my God, I don’t even know how I got here. I don’t deserve this! I’d like to thank Ken.
It's clear that she means 'I'm not sure how I ended up herein my life (e.g. on this stage, being honoured by all of you)'