Hi & welcome! Yes, having been around a number of horsey forums, I do think this is a particularly helpful & respectful mob
hope you enjoy it here!
Agree with Tiny. You can of course, attempt to force the horse to comply to you with a 'bigger bit' approach. This often works, but frequently also makes the horse eventually worse. I think it's best to take training as slow and gently as necessary. It's possible if she was ridden in a 'harsh' bit that she wasn't actually *taught*, only forced. I'd personally get the horse going well in a halter/bitless/hackamore first, before thinking about a bit, or use something like a french link snaffle.
I'd start on the ground, teaching/reinforcing yielding in all sorts of ways, to the halter as well as to fingertip & implied(bodylanguage) pressure on different areas. Then when you start out onboard, start out asking at a stand & then walk, mastering that before asking her to do same at a trot, etc.
I'd stick to an enclosed, safe area for now, such as an arena or small paddock, so you can *ask* her to respond to gentle pressure, rather than have to try to force her for safety's sake. I'd get her reliably responsive in that sort of environment before taking her out. Remeber too that horses don't generalise well, so I'd also start with the 'easiest' stuff when out, before asking for gradually more. - Don't gallop until you can w/t/c!
If you look up clicker training & also Parelli's 7 Games, you'll find some good info re the specifics of teaching.
Oh, nearly forgot to add, if you think your horse is just too full of beans, what is her diet & management like? Is it possible she's getting too much high energy feed, or is she cooped up or otherwise jumping out of her skin for some reason?
Also when did she last have her teeth attended? Has she got any body issues? Saddle fit? Checked out by a good bodyworker? Because it's possible that pain in her mouth or otherwise is why she's running through pressure.