1) Buy this modem+router, from this site:
http://www.ebuyer.com/product/52244
(It's about as cheap as you'll find, and both the site and product are very good.)
2) Make sure your PC has an ethernet connection, looking like a slightly larger and squarer phone line connection:
http://www.ust.hk/itsc/classroom/notebook/phot o/notebook_network_port.jpg
3) You forget about any modem your currently have, and connect the above product directly from phone line to computer (not forgetting micro fllter as usual between router and wall phone socket like you'll have now).
4) That's it! Set the router up as it'll say in the install guide, ideally putting a decent WPA password on the wireless, not that not just anybody can get in.
Assuming your daughter's laptop has wifi (she should know?), then she'll be able to connect by choosing your network name, and entering the password.