Why is the Queen of Spades in cards thought of negatively–or is she? What is the lore on her and is there any on any of the other cards?
Also, what is a Jack supposed to be? Is he the son of the King and Queen or is he the Knave?
And what is a Knave?
I haven’t my history of cards with me, but this is what I recall. I can look it up again and give you cites later tonight if you like.
The Queen of Spades is thought of negatively due to most all the spades being viewed as negatives. The Ace of Spades has been thought to signify death. Presumably, the Queen of Spades is the lady of death. If you look up Cartomancy in google, you’ll see that many of the Spade cards represent misfortune or strife. (here’s one: Этот домен продаётся). I do believe that the Spade suit is supposed to be like the Sword suit in Tarot. Many of the Sword cards represent adversity (although not necessarily defeat or loss). Several books I’ve read lately dispute that playing cards come from Tarot cards. They suggest that it was a parallel development. (http://www.pagat.com/ipcs/history.html), but that doesn’t mean that people don’t try to find commonalities between them.
The Knave is the Jack. Jack was, for a long time, the vulgar/low class term for Knave. I believe some Dickens story (Great Expectations?) refers to this. When cards started to have indexes on them (the number and suit in the corners), the name was “officially” changed to Jack to prevent: K=King, Q=Queen, K=Knave
Anything else? 
AbSimia
Absimia generally nails it, but I can add two things:
- Tarot cards date back from the 1430’s, and are, as absimia rightly notes, a parallel development. They were used (and are still used) for games, and weren’t used for cartomancy until the eighteenth century. (Cf. David Parlett, A History of Card Games.) The French game jeu de tarot still uses the tarot deck for a trick-taking game. (Side note: I’ve played jeu de tarot and it’s a great game.)
However, the Sword cards don’t represent adversity or anything else in the tarot deck. The Sword suit is just the Italian/Spanish equivalent of the Spade suit, and has been since the fifteenth century. You can still today buy an Italian or Spanish deck with swords, staffs, cups and coins as the suit-marks. The French jeu de tarot decks have the more familiar side-suits of spades, clubs, hearts and diamonds.
- Parlett suggests that the name “jack” for the knave originally stemmed from the game All Fours, which we know better now as “Pitch” or “California Jack.” The four objects of the game are to capture High (trump), Low (trump), the Knave of Trumps, and Game (total face cards, originally). Jack is a good old word for any such object in a game (for example, our familiar game of “jacks”). The name stuck to the knaves among All Fours players, who generally were lower-born than devotees of Whist. Hence Dickens’ observation about those who called the Knave “jack.”
In the card game “hearts”, getting the Queen of spades when you don’t want control is “heartbreaking” to say the least. I’ve heard the card referred to as “The Black Lady” by older, more polite players. I use a different nickname…
Now I’m wondering what a knave was in connection with the king and queen in actual reality. I thought he was their son but knave doesn’t seem like it would be a son type person. Did royal courts always have a knave around? I know he stole some tarts in this one poem… I learned onetime that the court cards were modelled on actual rulers, such as Henry VIII and Phillip the Good. One of the queens was actually supposed to be Queen Ann. But why are they facing certain ways, such as one-eyed jacks and it is always the same to have each king, queen, and jack exactly the same way almost on every deck of cards (except for rare exceptions like those Italian and Spanish decks that were mentioned above).
don willard: The bit about cards being representative of anyone is an old legend. The design of cards has been mutating over centuries now, and it still varies by country (I think). Here’s what Snopes has to say.