Yes infernal the crf230f is a four stroke and i would reccomend that for your wife because she won't have to shift as much and the power is easy throughout the gear unlike a 2stroke where the power band jumps out at you. Personally I prefer high performance 4 strokes over 2 strokes now just because they are less maintenence and the power out of a high output 4 stroke is insane. I am looking to buy a 2007 kx450f soon so that will be nice. Mainly the 2 strokes were phased out because of the emissions in california and that really killed the 2 stroke industry so they started making 4 strokes with more power and it's awesome. I swore by 2 strokes when I raced minis and moved up to 125's but I bought my first 4 stroke in 03 and I loved it. Any mid sized trail four stroke would be a good choice for her that's why I suggest the crf230f because it is the right size for her in power and size of the bike but she won't be overwhelmed by the power of a 250f.