@onionskins
Well, several of them are flatalists.
And the rest have... too excellent political marriages, let's put it at that.
They're basically terrified of their fiances who are just too good in some areas, and too... perfect in others.
And they're treating it as the political marriages they are (except for the later new girl)
Meaning they mean them all the well, but they don't fawn over their every idea.
Margaret and any other person in similar situations in other novels... they show attention and are cute, two things they don't get from their current fiancees.