Just one more thought: If she just wants a basic smartphone, either will work fine and they are equally on par with each other as far as out of the box stuff (in either case, you set up your email and your home wifi network, maybe change your wallpaper and your ringtone and you're off and running). So as a basic smartphone, either should be sufficient.
But the true power of Android is when you want to go beyond that. When you want your phone to go beyond being a "dumb smartphone" (which is how I refer to the iPhone and earlier phones in general) and truly being part of the new generation of a smartphone. Things like i talked about earlier where my phone is telling me to leave for appointments early because of traffic, When it's automatically silencing itself because I have a meeting on my calendar or I'm in a movie theater. When it's automatically telling me how long my commute is before I ever leave the house or the office (without asking it to). Where it's giving me flight information because it knows I have a flight based on a confirmation email or that it's on my calendar (I don't have to do anything special other than get a confirmation email). Where I walk out the door of my office and it texts my wife automatically to let her know I'm on my way home (but only if it's after 4:00, because otherwise I'm probably on my way to lunch or another meeting). Where I leave my house and it turns off wifi automatically to save battery, then turns it on again when I get back home. Where I tap my phone on a sticker on my desk at the office and it connects to my bluetooth stereo, starts Pandora, sets my volume control and starts playing music. Where I just turn it face down or put my palm over the glass to silence it if I need to.
Buy not everyone cares about that kindof stuff. I do though, and it's all stuff my phone does right now.