Car will not start

It is my daughter's car and every so often she calls and says her car quit running but always restarted. This time it did not. Turn the key and does not crank at all and fuel pump does not come on. I have changed the fuel pump, mega fuse and ignition starter switch under the steering column. No fuses are blown and from what I can tell relays are good. I have swapped some of them out just to check and they cannot all be bad. All other electrical things work, radio, windows, power locks, power seat. She does not have a lot of money so trying to help her out, any ideas would be much appreciated.