I looked into a few different electric bikes and kits when I moved a couple years ago and my commute got a bit longer. Electric bikes can be a cool thing for the right people and the right uses. The range is still a bit limiting but in your friend's case, should be well within limits, maybe even ideal. Depending on her commute (hills, etc.) and weight, she may need to charge the bike up at work for a full power return trip. For a cyclist that is already comfortable with 20+ mile rides electric bikes are not worth much, in my opinion.

Ten miles is a huge distance to a non-cyclist. Depending on your friend and her fitness level and goals, an electric bike could be the perfect first step to help prove that a cycle is a very real and valid option for getting around. The prices, however, can be a bit intimidating for someone not familiar with the cost of quality bikes.

There are a couple different types of electric bikes; throttle and booster motor. (I doubt these are the correct terms, but you get the idea anyway.) The throttle bikes are more like a motorcycle or scooter and can be ridden on electric motor alone. The booster type only supply boost when being pedaled. I think the booster type are much better. The rider gets excercise and increases their fitness level whether they are trying or not.

Batteries, of course, wear out. In a year or three (depending on care and use) of use, the range will shrink to the point that the batteries will need replacement. By the time this happens, she should have the bike experience and the higher fitness level to think more seriously about getting a regular bicycle instead of replacing expensive batteries.