lol don't you love how it's blatantly obvious that some people didn't read the OP and rushed to post what for lack of definition can be called propaganda.
OT: Both systems have their advantages
360 is cheaper and has the following exclusive games that may be interesting to her;
-Mass Effect 1 & 2
-Fable 1 & 2
-Alan Wake
-Viva Pinata
PS3 has bluray which would be useful if she likes to buy a lot of movies and has an HD tv. The exclusive PS3 games that may be of interest to her are;
-Uncharted 1 & 2
-LBP
-Heavy Rain
-Flower
In addition to that there are plenty of multiplat games like Rock Band and as you mentioned Bioshock that she would probably like too. Not to mention a plethora of games on XBLA and PSN.
Some games though have pretty complicated controls for a novice so you have to consider that too. I could see her having a hard time playing Uncharted or wrapping her head around Mass Effects rpg elements.
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