At this point in time there are the following who are currently considered full time QEII, Charles, Camilla, William, Kate-(Cambridges are new to full time), Anne, Timothy, Andrew, Edward, Sophie, Richard, Brigitte, Edward Kent and Alexandra. (13) (Sometimes there is discussion as to whether or not Timothy is full time.)
Phillip and Katherine Kent have more or less retired from full time duties though both still make appearances. (2)
There has been no statement yet from KP regarding Harry becoming full time yet though I do I believe that this will happen in the near future. No statement yet regarding Meghan either, so we'll just have to see.?
Meghan can be expected to be at the annual national events: Remembrance Day, Trooping the Color, Family events: Christmas/Easter, weddings, christenings etc.. She'll join in for other events related to the patronages that she adopts and most likely anything to do with The Royal Foundation of the Duke and Duchess of Cambridge and Prince Harry. (Expect a name change after the wedding.)
I believe that this is Europe's largest pool of "working" royals. ?
Meghan will not be paid an allowance from the state. Only the Queen and DoE receive money for their engagements. The Queen assists her relatives for their engagements from her Duchy of Lancaster money. Charles does the same for himself, Camilla, the Cambridges, Harry and soon to be Meghan with his Duchy of Cornwall money.
In the future I believe that we can expect Meghan to give speeches.