This is everything I could find for some nice Lizzo high notes (and some low). I think a lot of times she is way more into performing and doesn't pay attention too much to technique. That being said, it's clear to see from many of these performances she has the capability to go off.

Also I know a lot of people in my last Lizzo video said that the G6 is screamed and doesn't count, but here she hits it the exact same way and looks mostly relaxed, so I think it counts.

Thank you!