Sure, @jsmla. She'll have to give your name and site number to the guard to get in. He may tell her to park in the front lot and bus in but if you have space she can drive to you.
That works most times except when the Fort is busy and parking lots (and overflows) are full such as during holiday times. Then the way to do it is to put their name on your reservation when you check in so they can still get in. That's the fail safe method.