@Nata****
have them try for the 60 day covid extension, it's all they have available to apply for,
if they say no to that at the immigration office they'll have to exit/re-enter to get another 90 days
AND
some land borders won't let 90 day stamp countries bounce out and back SO if that's what they're going to do CHECK before they show up at the border thinking they can get out / back there.