Let me add an observation ( from jobanjo) :

 

 -- After NMF,  if  Opener rebids 2NT or 3NT, it implies 5 cards in Opener's minor.

 

  Work it out ! !

 

   Here is an example:

After     1D  1S  1N  2C! Opener then bids:

 

  2NT  has denied 3s [ no 2S bid ]

            "        "      4h [ no 2H bid]

            "        "      4c [ no 3C bid]

 

   So Opener is something ( if not exactly) like 2 3 5 3

 

She also said she "uses Gerber in some NMF auctions -- don't tell Lorne "