Fuel Pump or Filter???

Okay, so my sis-in-law's 98 Blazer wont start. It tries to turn over, but it will not completely start. My first guess is that it is not getting any gas fed to the carb. Could this be the fuel filter (possibly clogged) or does it sound more like the fuel pump. I would imagine that it is the fuel pump, but I would rather it be the filter. Any advise would be appreciated.

Thanks.

Can she hear the fuel pump prime whining noise when she turns the key to the on position before start?

Not sure. I will check that out tonight. I am assuming if that noise isn't there, then the pump is the fault.