^ Unfortunately my budget can't afford to drop $1000+ on the new bike. I'm hoping to find a decent frame-set for $100 or less and swap most of the parts over from her other bike that she isn't comfortable on.

As for light-weight wheels, I do already have some Rolf Racing XC wheels that are pretty darn light and in perfect shape, along with some decent quality 26x1.25" tires. I also have a shorter 165mm crank to account for her shorter legs and pedal clearance on the 26" wheeled bike with smaller tires.