Possibly. Some changes like the bony structure of your pelvis may never completely go back however with consistent exercise and healthy eating many women can even improve their body after pregnancy.
No. Our bodies are in a continuous state of change. We will never be the same, but you can come healthy diet and physical activity to achieve a new normal that you can be proud of.
No. One can get her pre-pregnancy weight back, and work out with weights to get in great shape again, but cannot truly get her "pre-pregnancy" body back. That is because a pre-pregnancy body is a different stage in a woman's life than a post-pregnancy body. One's age is older, and some permanent changes have occurred, especially after several babies.