Have you verified it is when any computer connects to the wireless network? The reason I ask is I have seen this a few times before, but it was with one specific laptop each time. The radio had gone bad in them, and it takes the channel utilization to 100% which knocks every other wireless device off line.
Edit: Please explain more on what you mean when you say her machine gets kicked off the network. Is the laptop still associated to the access point? Can it ping the gateway IP address? The reason I ask is you stated you put in a static IP address. This would lead me to believe the laptop i still associated to the access point. If this is true, this is more than likely not a wireless problem.