Check out UGA. I went to Maryland Undergrad and Georgia for my MBA. Maryland is my daughter’s (18) top choice but UGA is a close second. Sounds like she has all the same criteria for selecting a school as your son and has the same SAT so far with a bit higher GPA.
Georgia is a simple flight from DC and has ample transportation options from Hartsfield to Athens. Might not be as diverse as Maryland but should do the trick.
Go Terps and Dawgs!!