Meghan said in an interview preHarry that her style icon was French fashion editor Emmanuelle Alt
Meghan hasn’t found a more formal style influence, for her working duchess wardrobe. For really high profile events she cracks open Givenchy, Dior, Herrera.
But she needs to find some designers who are reasonably priced; hopefully British and work to her Style aesthetic.
She does suit that pared down American sportswear / casual style.
I think the Carolyn Bessette Kennedy style works well for Meghan. CBK was also a publicist for Calvin Klein, so that aesthetic works...
I would also look at Vintage Jackie Kennedy.
Meghan should also think about cutting her hair and embracing her natural curls whilst pregnant. She would look amazing.