It does have the sweet iron on it.
Did she ever take the bit good? Is this a new habit or something that you've always had problems with?
Put on a rope halter and pull down, if she raises up to resist keep pulling down if at all possible...but the minute she puts her head down release the pressure and award her...then keep doing it again and again and again and again until it's drilled into her mind that that is what you want.
Then try it with the bit and see if it helps
Yes, she had always taken the bit good, for me at least. Just a couple of weeks ago she decided to throw her head. It was so bad one time, I couldn't help move cows!
And thanks for the advice. Right now, she takes it well, but I have to be really careful not to bump her teeth. I think that when my grandma rode her, she wasn't very gentle and just shoved the bit into her mouth.