The struggle

Doing drills she has ball up at 9, great brush and IR. Full speed not so much. Any advice? How long will it take!?!?!?

That's the reason I'm not so convinced in segmenting. One of the greats on here teaches to always use full motions... I'm have mixed feelings

My dd does the same, she drills great palm up but full speed she has horrible ball position, unloading and getting behind the ball causing her to loss all her speed. I'm trying to have her focus on starting in handshake position and getting close to her ear on the way up?

This is always the challenge right? Drills are perfect.....full motion....not so much. After a lot of trial and error...here's what I have found to help...whether hitting......pitching.....fielding......with my DD and the players on my team. Do your drills..... get it right. With pitching.... here's what I found helped the most. Don't be greedy. After the drills.....ask her for 10 full pitches...No care in the world about the result. Don't care where it goes, don't care how it spins, don't care how fast or how slow, etc. THAT'S IT.... 10 pitches. I caught myself seeing drills going great, then moving to full motion expecting it to carry over....then doing nothing but yelling for the next 30 minutes while she reverted back to all the stuff we fixed in the drills. This is a long term commitment. Encourage them to REALLY focus on what they are doing for those TEN pitches. Exaggerate the point you're working on. Expect the worst....you'll likely see it. If you want to know how she feels as she adjusts to these changes..... try signing your name with your non-dominant hand. That's how she feels.....it's all wrong to her in full motion.

How long will it take? The answer is....As long as it takes.

This is THE struggle when instructing. Couple of thoughts in making the transition from static to dynamic movements...

1. Create overlapping drill movements. Example: Don't allow your DD to reach the top of her backswing in drill. Start backchaining the motion later than usual... only removing the hand from the side once her forward STEP (not leap) is well established. Her forward momentum should pull the arm "out of the backswing".
2. Incorporate a lean prior to stepping forward. Start with both feet on the plate... pitching side foot at a 45... and have her start to lean/fall forward. As in 1... have her keep her hand from moving (backchaining) until the stride foot leaves the ground. It should be a struggle (and a goal) to get to Show-It position.
3. Perform "Rocker Walkthroughs". There is no leap... just a forward step. The key... and the MAIN FOCUS of this drill is what I call 'Big Toe Kinematics'. The heel of the 'drive' foot must only make a rocking movement over the big toe.. AND ONLY travel forward. It (the heel) cannot move in any other direction. Simply rock it up. You'll notice that this articulation (when performed correctly) creates knee flexion... which allows the throwing-side leg to be in the throwing lane. Be strict... the heel can only raise up... and ONLY TRAVEL FORWARD. Any other movement is an immediate fail.
4. Don't let the front foot rotate the back foot. Stepping into a 90-degree plant makes it difficult for the rear foot to rock up and over the big toe (shoelaces to catcher) as noted in #3. Plant at 45 or less. She might square out a little... but that's ok - as long as she knows that her torso (four corners) must stay still.

#3 is your transition drill... but without proper performance of the others... it's a very, very long road. Slowly add juice to the walk-through. Don't forget to toe-out A HAIR when doing them... but be sure it's not too much... as excessive toe-out makes external rotation of the femur easier... which will pull the throwing-side leg out of the lane... and is easily the one of the largest reasons kids can't find brush (the heel travels rearward, then forward... figure-4 kicking.... crow-hopping... etc.)

it's not uncommon. My DD has the same issue. DD's progressed from doing great in drills to almost great in full pitch practice, but only to revert back to her old self when throwing to a live batter.

for DD, it's taken about 4 months to transition from doing great in drills and almost great in full-pitch practice but still mediocre in live pitching.
and that's practicing 3x a week. YMMV.

frustrating, it has been. but a marathon it is, a sprint it is not. dang. i'm starting to sound like Master Yoda.

One more tip to try. You will find that when doing the movements without a ball the pitcher is almost flawless....but as soon as she throws with a ball, things revert back. The weight of the ball creates a different set of timing/balance and slightly different muscle recruitment.......so do the movement throwing a whiffle ball....then gradually increase the weight of the ball she is throwing...a great use of underweighted balls.
As others have stated....it is a process requiring patience.

I would suggest throwing into a tarp or net that is @ 20' away. This allows your DD to concentrate on her mechanics vs. the results of the pitch.

Don’t beat her over the head with it but get some videos on your phone to show her.

(Videos of her)

I want to first start out by saying that I am a parent not a coach.....so I am no expert. However, I had some success by getting my dd to freeze during certain points in her motion that is/was being tweaked. She knows before we start that she will not be releasing the ball. As she makes her way through her motion....I say freeze. Most of the time she will stop and immediately move her hand where it is suppose to be....or she will realizes that she is leaning and will fix herself...etc. This really doesn't fix the problem but it makes her aware of what she is doing. When I say freeze and everything looks good I say great job "do you feel the difference". Sometimes my dd is convinced that she isn't doing something that I am pointing out...so this works for us. I remember the clips of your DD. She is a beast! I know you are frustrated with trying to fine tune somethings. I hope for the best! I know she will get it! As I think about the clip what I remember is that at 8 your dd corrects ....its from 12 to 9 that I remember got a little palm downish. So focusing on that portion of the motion may help.