I would pull her now. Even if there is no other option, you cannot keep her in that environment. She is young and can/will find another sport. She has already told you she can't take the yelling anymore. She is ready to move on.
THIS! No choice but to pull her. And to be honest, unless she is really begging to find another gym, I would not drive that far for an 8 year old on level 4. I'd find other activities. She is young enough where there is a whole world of stuff she can try and readily learn and excel at, especially with her gymmie strength. And at level 4, she is not yet in so deep where it feels like there is too much already invested.
My 11 year old quit as a level 8, and has not looked back (like almost seems to want to forget gym or deny it or something). Meanwhile, I look back to the very first time she told me that she was unhappy (somewhat similar in terms of mean coaching, pushing her waaaay to hard and fast, nasty comments about her worth when she was 8 years old and struggled on anything at all, etc) and I kept her in it because of her "potential" (yep, you can insert a big ole eye-roll here). And over the next several years, there were many many good times, but many many bad as well.
But, if I could rewrite history, I wish that I had pulled her way back when she first said something and then helped her explore everything else. Even though 11 is still young enough to try new sports, she feels like she can't necessarily compete at the level she'd like to in something like soccer or swimming etc because those kids have been doing it for many years. While I disagree and think she could do anything after some practice, I can understand her feeling that way. She is used to being a high level competitive athlete, so at this point, jumping onto a rec level team doesn't bring her the same joy of competition.
Although she does not seem to hold me responsible, I feel like I am. She told me she was unhappy and i convinced her to "stick it out" at the cost of all of the other things that she could have been exploring.
just food for thought...