Both girls have a similar issue, it must be genetic! They don't have a lot of IR because their arms are too straight. What I use with pitchers who have this issue is to have them make a small ball circle. If they tighten the circumference of the circle they will have to keep their arm bent/flexed. I like to have them start from the 'release' position but if they don't use that position in any drills or warmup then an easier full motion will also work. It's better if they focus on the ball rather than the arm, but you can point out that the arm is flexed/bent. It should feel a lot different.
Her orientation around the circle is not bad, but she isn't whipping. She is just pushing the ball through release and she isn't getting any of the angular acceleration that is desired. Even in the original video, the apparent IR is just a forced move by her AFTER the ball has been released. You can see she flips her hand over when its about chest high.
This is just a result of progressing too fast. She has not learned what a natural whip feels like and maybe thinks that simply turning the hand over means she is doing it correctly. Forced IR isn't a whip.
She's really close, just needs some detail work on catching the whip and learning what it feels like for it to occur naturally.