If she's not balanced, you have no hope of getting collection. Collection comes from years of hard work, gymnastic training and skillfull riding. It is not something that you can do in one day by strapping the horse's head down and kicking.
At this point in time, with a green horse, all you should be doing is establishing her 'buttons' and 'gears'. She needs to get off your leg immediately, come back to your rein and to your seat. You need to have a perfectly established 'stop, go and turn', and a horse that is willing to go forward and stay forward, until you say otherwise. From there, you can begin introducing a little leg yield, and establishing more bend through the mare's body, which will gradually help to develop her carrying capacity through the hind quarters, and encourage her to swing through the back - the beginning of the stepping stones to collection.
I see you are at Mt Compass, not far from me. There are some good dressage coaches around the area, if you are interested I can send you a list of some people. Or if you were really keen, I would be willing to come and give you a bit of help or have a few sits on your mare to see what I can give you to work on.