Well, if she's too short, there's nothing either of them can do about that. The most she can accomplish in that moment is to call him out for being a douche about it. Which might make her (and us) feel better, but doesn't change anything, so you can see why she'd let it go and just move on to the JSA plan.
(I won't even pretend to argue that making her that short for the sake of that plot point isn't beyond asinine, of course, her having been quite obviously, sometimes explicitly, always visually in the 5'10" range for her entire existence - when you can tell a woman in a wheelchair is taller than her ambulatory partner under five different artists, her height is obviously a significant feature - and I think we figured out on S_D 1.0 that the requirement wasn't chronologically accurate anyway, but within its own context it's a defensible plot point. Stupid though it is. >.<)