What are flat and round characters in "the outcast of poker flats"

First you need to know what round and flat characters are --

A round character is a major character in a work of fiction who encounters conflict and is changed by it. Round characters tend to be more fully developed and described than flat, or static, characters. A flat character is a minor character in a work of fiction who does not undergo substantial change or growth in the course of a story. Also referred to as "two-dimensional characters" or "static characters," flat characters play a supporting role to the main character, who as a rule should be round. (Round Characters and Flat Characters)

Now, list the characters from the story. After you do that, we will decide if each one is round or flat.

I know what they are but who are they in the story?

John Oakhurst: Professional gambler who is forced out of the town of Poker Flat as an undesirable because he wins so much money from the townspeople.
The Duchess and Mother Shipton: Prostitutes who are also banished from Poker Flat.
Uncle Billy: Thief and drunkard who is likewise forced out of town.
Tom Simson: Young man who leaves town and joins Oakhurst and the other outcasts. He admires Oakhurst, who returned $40 he had won from Billy after feeling sorry for him.
Piney Woods: Tom's sweetheart, who leaves town with him. They had planned to marry in Poker Flat.
Jim Wheeler: Resident of Poker Flat who bemoans the loss of money to Oakhurst.
Jake Woods: Piney's father. He is referred to in the story but plays no active role in it.

Let's name the obvious round and flat characters first.

John Oakhurst = round.

Jake Woods = flat.

That leaves --

The Duchess and Mother Shipton: Prostitutes who are also banished from Poker Flat.

Uncle Billy: Thief and drunkard who is likewise forced out of town.

Tom Simson: Young man who leaves town and joins Oakhurst and the other outcasts. He admires Oakhurst, who returned $40 he had won from Billy after feeling sorry for him.

Piney Woods: Tom's sweetheart, who leaves town with him. They had planned to marry in Poker Flat.

Jim Wheeler: Resident of Poker Flat who bemoans the loss of money to Oakhurst.