I'll second GLC. I too am an engineer. Grades matter and your drive and purpose in the engineering field matters very much. If she wants to take a gap year, she BETTER have a focused purpose.

I dropped out of HS and never got a GED or what ever that thing is called. Dropped out in Junior year and went straight to an IVY League school. I was determined and I was very focused on what I want to do in my life. I didn't have second thoughts about it. So I'm bit of an odd duck. Also didn't take any break from BS degree to my Masters and I quit during Phd program. I wasn't interested in becoming a tenure track professor at any university although I was a research staff at my alma mater. Different department though. I have loftier plans than to collect more wall/fly paper (honors degrees etc. My father already did that with his MD, Phd in BioChem... or other members of family uncles aunts cousins...) Only one in my family NOT to have a college degree is my sister. I think she was overwhelmed with all the "fly papers" on the wall.