Be sure to check out the Romik running boards (at www.Romik-USA.com
), which are essentially a combination of nerf bar and running board. And they are made of stainless steel (or black powder coated), so no rust problems and a 10 year warrantee. My wife is also 5' and she is very happy with them. They also don't require removing the front mud flap, so combined with the running board surface, you have some real side protection from winter muck, or mud and gravel.