Libbert, who will take over in May, replaces Helen Johnston who is set to join IPC Media rival title Now! as editor later this year.
Prior to Top Sante, Libbert held positions at various Emap Consumer Media titles including More, where she was acting deputy editor, and Closer, where she was news editor. She was also assistant editor at Take a Break and contributing editor at Haymarket's Eve.
It will be her second stint at NW, having previously been assistant editor at the title.
NW said it intended to increase its online presence throughout the year, following the relaunch of its website.
Libbert said: "In the coming months, I aim to make the title even more of a must buy for 20 to 30 something women and to simply make it great."
In the latest six month magazine ABC circulation figures for July to December 2006, NW dropped 4.2% to 222,076.