I've also seen 5'. I think that's about right, because she usually wears very high heels. If you look at her next to her husband Jason I believe he's around 6', and take into consideration her heals.
Here's a link to photos of her from wireimage at the invincible premiere. Look at the heels on those shoes.
http://www.wireimage.com/SearchResults.aspx?igi=206742&s=Paige%20Turco&sfld=C&vwmd=e