The shanks circular. There is a chin strap and I believe it's chain. What are you thinking?
If you ride her again, I'd put more bit in her mouth, so you have a better chance of getting her stopped if she would buck again.
There is a real good bit that I use alot that is called a correction bit. You would probably get alot of negative imput for using it, but it is really not that bad. It is hinged on either side of a port, has short shanks and requires a curb chain.
Here's one:
The head stall and curb chain hook to the top rings, and your reins at the bottom. That would be the first thing I would do if I was going to get back on her. At least for awhile I wouldn't worry about hurting her, which it won't really, but it will get her attention a lot quicker then an O ring. Just trying to help give you some things to try if you do try her again.
Becky