The wide range of downtime after tummy tuck
We often recommend two weeks after tummy tuck, and this is about right for most. We also have some be out and about after one week, and a few who may require three to four weeks. Like most things, recovery will follow a bell curve, most in the middle, some at either end. Your friend is not wrong or especially slow if she needed the four weeks to get back to things, she is just at the further end of the curve.
Best of luck,