I haven't tried making it lower, but I have to ask, how new is the vehicle and what was she driving before? I have to admit that when coming to the Ody, there was a little bit of an adjustment period, now I'm used to it and wouldn't go back. Since its a 2010 and you registered in September of 2010, I'm guessing she can't have been driving it for all that long. I would wait and see if she gets used to it. It doesn't sound like its all that big of a deal. Also, I'm not an engineer, but I can only imagine that making some sort of change like that could potentially compromise safety systems. (Airbags, seatbelts, etc....)
Yeah, we just bought it about a month ago and we are still getting use to it. I have no problems since I drive 5 different cars at any given time. My wife use to drive the Accord all the time and occasionally the Jeep, but I did tell her the samething. She might be nervous about driving the Odyssey and it's the nerves that are causing the tension in her legs. But she swears that its the height (yeah, I know). I checked the seat belt height to make sure it will still be across the shoulder, but I didn't even consider the airbags. Thanks for pointing that out and I have to check into it.