If it's more than six months since you gave birth and you are still incontinent, so it's time to consult your doctor. Pregnant women often experience stress incontinence, particularly in the latter part of pregnancy, when the fetus becomes heavy and drops into the pelvic cavity. In some cases, during the pushing stage of vaginal delivery, the pelvic floor muscles are damaged causing the bladder and bladder neck to drop, which in turn, makes it harder to retain urine.
Although duration and difficulty of labor and the size of the baby and contributing factors, there is no way to predict who will experience postpartum incontinence. Most women will regain their muscle control within six months after giving birth. Try kegel exercises , which will help you for fast healing process. 
Kegel exercises consists of contracting and relaxing the muscles that form part of the pelvic floor. The aim of Kegel exercises is to improve muscle tone by strengthening the puboccocygeus of the pelvic floor. Kegel is a popular prescribed exercise for pregnant women to prepare the pelvic floor for physiological stresses of the later stages of pregnancy and vaginal childbirth this is according to Wikipedia.
Urinary incontinence isn't rare but it is not normal. Women should not be incontinent the rest of their life, just because she had a child.
