Thanks for your response.  It seems the internal wireless card was not sufficient to support 5g.  We have updated her card and everything is now connecting.
My daughter has a XPS L502X laptop which will not connect to 5g on a Linkskys WRT1900ac router.  Any thoughts on how to get this to connect or will her laptop just not connect to 5g?  Thanks!
Connecting to a Linkskys WRT1900ac router