If you're asking for contact, your reins are way too long. There's so much emphasis on riding back to front these days, people get confused and forget that you still have to shut the door up front or all that energy you're trying to create will go right out the other end. In both pics, I would suggest moving your hands forward. They should be in front of the pommel, not over it. Raise your hands up about a pinky length above the withers. Take up the slack in the reins so that you can just feel your horse's mouth. Ideally you want to create a straight line from your elbow to the bit. As you walk along, focus on following the motion of your horse's head with your hands, so that you're keeping a constant but soft contact with her mouth. It can be very difficult to find the ideal contact spot where you're not pulling on her mouth, but you haven't thrown it away either. Try establishing the contact with her head poked out like it is in the pictures. Your goal is the get her to where her nose is just in front of the vertical. At this point, time to switch your thinking away from the reins. Now your job is to use your seat and legs to drive her up into the contact. At first you just want ask for a more lively walk, just enough to give her the idea that you want a little more. If she braces against the bit instead of softening to it, try some circles or serpentines to start suppling your horse around your legs. A supple horse is ultimately what creates a balanced horse. It has zero to do with the head. Make sure you're providing a nice, soft leg for her to bend around. Once she starts to balance herself, she'll start to feel lighter in the bit and hopefully chew on the bit a little. You'll find yourself taking up slack in the reins as she becomes more balanced and becomes shorter in her frame and she engages her hind end. There's like a zillion more pieces to this puzzle, but for starters just find ideal contact and then drive her more forward into that ideal contact and see how she responds. If she has never moved this way before, please know that she will be using a different set of muscles than she is used to, so don't ask for too much for too long. Sorry I wrote a book. Good luck.