Technically, X is 28 and the Crown is 25 right now because X's birthday has already passed and the Crown's is still coming up in the current year the story takes place in, but otherwise yeah there's a 2 year difference between them!
As for the others, R is 23 (turns 24 later in the year), D is 30 (birthday has already passed) and A is 26 (turns 27 later in the year).