I think she will be exactly the same afterwards as she is now. If she is a puller you should invest in a head halter (there are several brands like black dog, gentle leader, halti). They fit over the dogs nose and neck and means that you can lead the dog rather than them pull you. It is the same type of equipment as a horse halter (you would never walk a horse on a collar!) See an experienced vet nurse who can help you fit the halter properly and will give you tips on getting your dog used to it, and how to use it properly to avoid hurting the dog (if you jerk at the halter you can injure the dogs neck). You will be amazed at the difference. They also don't restrict the dogs mouth (unlike a muzzle) so they can still pant while they are exercising, and drink water etc.