I agree with both Drs. Placik and Pollack. I have performed this operation several hundreds of times and I have never come across such symptoms.
It DOES sound like your wife may have EITHER an entrapment syndrome, a neuroma or an atypical pain syndrome.
In the process of tightening the rectus muscles and bringing them back to the midline, the fascia lining of the muscle is stitched together. The nerves supplying the rectus muscles are SEGMENTAL (they penetrate the side of the muscles every few inches) and are MOTOR (muscle moving) nerves NOT sensory nerves. The problem your wife complains about, on the other hand, is seen with sensory nerves which run in the fat ABOVE the muscle and are NOT normally caught in the plication suture.
Before undoing the repair needlessly only to find out that the pain persists, I would suggest that you may want her to see a Pain specialist. IF he/she can locate a single location where the pain starts and that pain can be numbed up - this is must likely a neuroma which is totally treatable. If on the other hand the pain cannot be reduced with a local block, it is more suggestive of an atypical pain which could be managed with certain medications.
Having a tummy tuck does NOT preclude your wife from having a baby. But - a pregnancy is likely to take away the flat tummy created by the operation. As such, plans for more children should have been discussed before the surgery.
Dr. P. Aldea