Does she like any particular treat that she usually gobbles down instead of playing with? That helps for training rabbits to sit.
I've only raised commercial type breeds that don't sit, but I've helped some 4-H members with their showier breeds. Initially it helps to use some sort of square rest, so the rabbit's bun and one side are against a surface, which trains them to sit square. Use the treat to tease her to sit up straight, and back. Sometimes, it's most effective to lift up her front end by pushing gently on her chest until her forefeet don't touch, then set her down with her forefeet just in front of her back toes. The pose should look natural and relaxed.
Some rabbits do bite, but you can't let them win, or they'll learn that biting means they get their way. That being said, I've had very few rabbits bite me while being posed. Usually they're cranky to begin with (such as from heat or stressful play). The key is to work with her when she's in a good mood. If she does happen to bite you, just hold her in place until she settles down (might mean pinning her by her shoulders, or holding her up off the ground, depending on how she's reacting; I'd say scruffing might be an option, but since she's a pet, she's probably not used to being handled by her scruff [which you'll have to work with her on eventually anyway if you plan to show, since the judge will need to flip her over to check nails, belly color, vent, and teeth]), and then try again. Get one more decent pose, treat, and then call it a day at that point.
also I apologize for all the bars on the cage
