I own the CW40 and have use to own the CW9 and would think either would be a fine choice. Here are my takes on the CW40 since it's what I am most familiar with.
Pros:
- Size- the pistol is narrow and can be comfortably carried in a wide variety of holsters and positions. It nearly disappears when I wear it, and as a thin figured guy, it is nice to have it hold tight to the body. With it's size, it's also has a big enough frame to get a nice purchase on the grip without the need of mag or finger extensions. For me this just adds to the accuracy I can obtain with a DAO trigger.
- Weight- it isn't a heavy pistol, making it very nice to carry. However it isn't a flimsy and can handle the .40 well.
- Rugged- They are built very tough, I have had no problems with rusting, and the polymer that Kahr uses has stood up very well and does not show any signs of wear after repeated use and a little abuse
- Reliability- All of the CW's I have fired have been 100%. The factory does recommend a 200 round break in period before the pistol is considered to be completely reliable. During the break in period I had no problems, although I have heard stories online of others having issues during and after this time.
- Ease of use- It is a simple system, easy to break down for cleaning and very simple to use.
- Price- they are very affordable pistols.
Cons:
- Fixed front sight- the CW models don't have a dove tail cut into the frame, so the ability to change out the front sight for a night sight is not there. I find that the stock sights work well, but it would be nice to upgrade if desired.
- Magazines- The cost of replacement magazines is a little high, especially for what you get. You also have to contend with a single stack 6 round magazine in .40.
- Recoil- Although I think that the CW40 handles the .40 well, it is a snappy round and it is not as nice as the 9mm. I found that the aggressive grips would eat into my hand while shooting the .40 and ended up putting a houge jr. grip on to help with long outings. I would think if your daughter finds the Glock .40 too much, she would probably find the CW40 to be a little too much.
They are great little guns and I have been very happy, but there are a couple of things I would not if you do decide to make the purchase for your daughter. One, they aren't meant to be a range burner. The polymer rails will wear and even fray towards the back of the frame if not kept lubed well and is shot a ton. While this hasn't caused any problems for me, it was a concern when I started noticing it. Also when when assembling the pistol after cleaning, be sure to seat the slide release properly with the spring. It's really easy to crimp the spring and get it stuck pretty bad. Once you do it once, you will never do it again
Overall, I highly recommend the line, and Kahr in general. The more expensive guns are great, but even the lowly CW's make a fine and reliable companion. Hope this helped.