Set up a wireless network with a USB modem

Hello, my sister has a network consisting of three laptops. she lives in the boonies with no access to broadband. she has had satelite internet but it is just as slow as dial-up. Now she has a verizon usb modem. this is where the problems start: which ever computer the modem is connected to is the one that gets the internet connection with the others getting nothing. she has a wireless router but the modem does not see it and vice versa. when i do an ipconfig/all, i get a class A ip address and a class D subnet mask. what I need help with is how to get the modem and router to like each other and to set up a secure network.

confused