Oh, the Yamaha Storia is a pretty neat guitar! Don't let the initial setup mislead you; once you've adjusted the action and swapped out the strings, it really comes to life. It's designed specifically with beginners and intermediate players in mind, featuring a comfortable body size and smoother tone woods that make it quite enjoyable to play.
Regarding the action being high, that’s not too uncommon straight from the factory. A excellent set-up will definitely make a world of difference. Make sure to check not just the bridge height but also the truss rod adjustment. Sometimes a slight tweak there can improve both the action and overall playability without needing more invasive work.
For restringing, consider what kind of sound she’s looking for. Lighter gauge strings might make playing easier for less-experienced fingers while still giving a full tone.
It’s cool that you’re helping out with selling these guitars – getting them in tip-top shape will definitely help in finding them new homes where they'll be appreciated!