You could try giving your daughter's PC a fixed IP address.
In her computer, while the connection is working, go to "Start > Run" type CMD and click OK, which will open a Command Prompt window. Type IPCONFIG /ALL and press Enter. This will list all of the network adapters in the PC together with their details.
Make a note of the IP address and Default Gateway for the adapter that connects to the wireless router. Close the Command Prompt window.
In the Network Connections folder, right click the adapter that connects to the router - presumably the "Wireless Network Connection" - and select Properties. Highlight the entry for "Internet Protocol (TCP/IP)" and click the Properties button. In the next box that opens, click Use the following IP address and enter:
IP address - 192.168.x.25
Subnet Mask - 255.255.255.0
Default Gateway - 192.168.x.1 (the address you noted earlier, which will be the routers' IP address)
DNS Server address - 192.168.x.1 (same as Default gateway)
The third "octet" of the IP address, which I've shown as 'x' must be the same as that in the addresses you noted when running IPCONFIG /ALL and this varies with different makes of router. For the computer's IP address, I've suggested a fourth "octet" in the IP address of 25 to avoid any conflict with either your address or the router's which are already in use.