Well, all of the discussion and waiting and arguing and hypothesizing is finally over. (Yes, I've pretty much stayed out of the discussion to this point. I knew that it was all in vain until the College of Arms did its work. That's why you've not seen any discussion of the possible coat of arms for Meghan Markle, the newly-married Duchess of Sussex.)
Kensington Palace announced this morning the new coat of arms which has been assigned to HRH the Duchess of Sussex.
Adopted: 25 May 2018
Coronet: Coronet of a child of the Heir Apparent
Quarterly 1st and 4th Gules three lions passant guardant in pale Or armed and langed Azure (England), 2nd Or a lion rampant Gules armed and langued Azure within a double tressure flory counterflory of the second (Scotland), 3rd Azure a harp Or stringed Argent (Ireland), the whole differenced differenced by a Label of five points Argent, the first, third and fifth points charged with an Escallop Gules (Prince Harry, Duke of Sussex); Impaled with a shield Azure a Feather bendwise Argent quilled between two Bendlets Or all between two like Feathers Argent quilled Or (Duchess of Sussex).
To the dexter the Lion as borne and used as a Supporter by the Duke of Sussex and to the sinister a Songbird Argent unguled and gorged with a Coronet of a grandson of the Sovereign. The songbird is white (argent) and and has about its neck (is gorged with) the Duke of Sussex's coronet. Both the claws and coronet are gold (Or).
Of grass proper growing therefrom golden poppies and wintersweet both flowering proper.
The blue backgrounds of the shield represents the Pacific Ocean off the California coast, while the two golden rays across the shield are symbolic of the sunshine of The Duchess's home state. The three quills represent communication and the power of words. Beneath the shield on the grass sits a collection of golden poppies, California's state flower, and wintersweet, which grows at Kensington Palace. The songbird with wings elevated as if flying and an open beak, which with the quill represents the power of communication.
Mr. Thomas Woodcock, Garter King of Arms said: "The Duchess of Sussex took a great interest in the design. Good heraldic design is nearly always simple and the Arms of The Duchess of Sussex stand well beside the historic beauty of the quartered British Royal Arms."
You can see more at such sites as: https://www.royal.uk/her-royal-highness-duchess-sussex-coat-arms and https://www.msn.com/en-us/news/world/pacific-ocean-features-in-new-royal-markles-coat-of-arms/ar-AAxNcZj?ocid=spartandhp&ffid=gz, among others.