I have found that if a green horse is going to try to buck they'll do it when pushed into the lope for the first time with a rider. You need a saddle on her so you can balance properly when she starts her lope for the first time. Any unbalance will sometimes make a horse fearful & cause them to buck from fear of carrying an unbalanced load at that speed. Also you most definatly need to be in a round pen so she can't start running too fast & getting her speed outta control.

It's easier to make them go into the different gaits if you practice lunging her with voice commands, like walk, trot, lope & whoa. That way when you get aboard & say the commands they will go into them with but little pushing, even the lope. But if you don't use your voice, then you're just gonna have to get her in a long trot & keep urging her more & more till she finally breaks into a lope. And usually it will be a fast lope when done this way from all the hustling you're gonna have to do. So be prepared for lots of fast hard trotting & lots of long hard hustling, as it usually takes lots to convince them what to do this way...& it's usually a pretty fast lope too...lol...