and everything AYE FEE said about this city is correct.  But the one thing I have to mention, and I know I sent Cutiepie2000 a PM, is that Fresno is really a college town.  The city is really devoted to the school, it comes out in droves to the stadium for football games and other games, and tail-gating is the thing to do.  Fraternities and Sororities are big in Frenso, there is Fraternity row off Cedar and Barstow.
If you love fruits, then Fresno is the place for you.  The university has it's own farm and farmers market (the best grapes this side fo the yosemity(ms)

  ), it even makes it's own alcohol (and you can take a wine tasting class..I did 
 
 )  It is just like a big city, the only reason it looks rural is because it's FLAT.  
Fresno has some beautiful HUGE homes that cost more money then a little bit

 , during x-mas, you can drive down Candel Stick Lane.  The Fresno fair brings out the family in everyone, the Fresno Relays are very fun, and all the concerts that university sponsers adds some class and cluture to the city.   (why do I sound like a PR person for Fresno 
 
I think your sister will like it.