If the computer is just a couple of months old, I would suggest going thru Dell and the warranty the computer must still be under for the BSOD (Blue Screen of Death) as it is generally called can be caused by an assortment of different things... from program conflicts, memory chips not securely mounted, or defective graphic cards, and on and on - most hardware related . Assuming she has tried a Safe Mode startup (tapping the F8 key at bootup, selecting safe mode or Last Good Configuration ) ...... Should have a help number for Dell within her paperwork or available online at the Dell site .....
That said, there is a
Vista startup repair feature that is included with Vista... either on the install disk or possibly already installed on the hard drive...... Here is a link she could try which shouldn't cause any problem with warranty repair if it is needed ....
http://blogs.technet.com/fareedmk/archive/2008/05/04/windows-vista-blue-screen-on-start-up-what-to-do.aspx .....
As a final thought/trick/idea..... take the battery out of the computer and just run it on the electrical power.... go ahead and try a boot up and see if the BSOD disappears..... this has worked for some with Dell Inspirion laptops... later replacement of the battery and all returns to being OK.........
But if the simple checks and tries don't work, then the Dell warranty effort should solve the problem for sure.... Hope she has a back up of her data and things she would want as Dell likely would replace the laptop and of course anything she had on the hard drive would be gone forever......

....... In any event...... good luck and best wishes as always