old catholicfag here and FLOTUS outfit when she met the Pope, yes even the head covering and color, is not suspicious in any way. Nor is Ivanka's, as Ivanka is simply taking her cue from Melania.
The dress, color, and head covering might mean something, yet it was very common when I was growing up, still common in some countries, and it's making a slow and possibly short comeback (head covering / scarf in US / Canada).
Doesn't mean there's not a double meaning as Melania often has a specific message she wants to send with her wadrobe.