connecting new laptop to network printer

I have a 3 PC home wlan connecting through a G router.

1) is an XP laptop to which the printer is connected directly by cable
2) is a Windows 7 laptop
3) is a NEW Windows 7 laptop

#1 can obviously print because the printer is connected to it by cable
#2 can also print to the printer via the wlan

The problem is with #3, the new laptop running W 7 64.

It is on the network, connects fine to the web via the router *but* I
cannot get it to see the printer connected to the XP laptop so I can
install it or whatever needs to be done.
I tried to "add a printer". It searches but does not find any.
What to do?

Thanks.
Jeff