Connecting an extra computer to Internet

[Paul Smith]

Dear All,

I have a cable-based (not optic) modem/router to connect to the
Internet (ADSL), which works fine. However, a friend comes in from
time to time, bringing her laptop. Is there some cheap and easy way of
letting her laptop to connect to Internet? Unfortunately, I cannot see
any place in the modem/router to connect an extra cable...

Thanks in advance,

Paul