(Going by my own research and talks with my docs) From what I hear, the kids are about the same as adults. What's making this flu so scary is that the medial age of death from it is 31, with the highest numbers around 24-35. The elderly (which are usually of the highest risk) are handling it much better than us young guns. What happens is this flu (H1N1) is attacking the lungs in a much larger, deeper way than usual flu's. In response, the immune system attacks it aggressively, and floods the lungs with too much fluid, leaving them badly infected. Then you get a really bad bronchitis (which happened to me) which can then lead to pneumonia (which happened to my father). People with weaker immune systems arent having the overly aggressive attacks by the immune systems, so they are actually fairing better. Since your daughter is 4, she probably has received the pneumonia vaccine as a baby, which is good. The vaccine lasts for 10 years. Right now they are advocating the pneumonia vaccine as being more important than the actual flu vaccine. Its the secondary infections you have to worry about. Just keep her quiet, give her LOTS of fluids and she should be OK. And if you can get it, tamiflu is helping greatly, but I am not sure how old you have to be to use it.