Well, one thing, she's not yours, so to get angry over changes made to her is rather immature. She is not your horse, so you don't have say in how she is kept up...and don't take this the wrong way, but you just gotta deal with it.
As far as the round penning and tools I use; I use both, actually. But for the most part I usually just use a coiled up lead...doesn't have to be a longe line, ust something you can flick toward her hip to get her to move away from you. And that is whether you are asking her to move out, or to turn...you want to teach her to turn in toward you with her front end, with her hip away from you, otherwise she is giving you her defensive end. With a whip, I have found it's not as 'surprising' to the horse, as the lead is when it comes coiling out at their hip...you likely won't touch her, but she will get the idea "turn in" "face you".
I don't really care for grass round pens either, so be very careful how you work her in there...it can be so much more unstable than a dirt pen which you can rake down if necessary. That's just my personal preference though...Lol!
Lesson From Your Horse: When you' re tense, let me teach you that there are lions in the woods, and we need to leave. NOW!!
