An ex-gambler wrestling with addiction, is forced to win back her daughter by playing her abusive mother in law in a winner take all game of poker.

I absolutelyy love this logline/story. If you can make the logline even better, great!!

Consider the following:
“An ex-gambler and her estranged poker champion mother-in-law compete for sole custody of her daughter”

The addiction and abuse references — B story plot points.
Keep going, would love to watch.

Sounds great. I see it like Rocky 5, where he doesn't wanna fight and it ends up a street brawl.