couple of women members of my riding group ride Scott bikes (i dont know if that Contessa or not). They are very happy with their bikes. My general idea of Scott bikes (hardtails) are - they are light, well made, good frame, nice geometry for single track or trail riding. Hard to go wrong with scott bikes.
one caution: if you are buying online be very sure about the fit. if it fits your wife then its great. I think SierraTradingPost has a no question asked return policy. So, if it does not work, you can alweys return it.
I hope my wife does not see that bike at STP, then I may have to buy it for her. Thats a sweet looking womens bike. good luck.
Success is a lousy teacher. It seduces smart people into thinking they can't lose. - Bill Gates