Sydney's 200 PR of 22.39 is from college, not high school.
Salwa Eid Nasser had PR's of 22.51 and 49.08. Then she decided to use drugs, skipped a bunch of drug tests, then ran 48.14 WHILE she was being investigated, and then got suspended. Good riddance.
Also:
Valerie Brisco-Hooks - 21.81 / 48.83
Chandra Cheeseborough - 21.99 / 49.06
Sanya Richards-Ross - 22.09 / 48.70
Allyson Felix - 21.69 / 49.26
Sydney ran a 400 in college, and she couldn't break 50 seconds. Sydney ran leadoff on a 4x400 as a pro at Mt SAC Relays in 2019, and she couldn't break 50 seconds.
Sydney ran a Diamond League 400 race as a pro in 2019 and she couldn't break 50 seconds. Sydney ran a 400 last year and she couldn't break 50 seconds. Sydney ran lead off on the 4x400 at the Olympics last year, and guess what? Once again, she couldn't break 50 seconds.
Could Sydney run sub 50 at some point this year? Probably.
But sub 48? Absolutely not.
Once again, the only 2 women in history who broke 400 were A) sub 22 200m runners, and B) on a large amount of steroids. Sydney is neither of those things.
And FYI, 100h speed isn't directly related to 100 flat speed, so her 100h PR has nothing to do with it.
Sorry that your "Sydney sub 48 bubble" has been burst.