The gambling angle is pretty much a Tower of Luck (the temple of Tymora in Waterdeep) orthodoxy. While gambling is somewhat in Tymora's purview, it's not a common focus of her followers, which tends to be more "fortune/fate/karma/adventure" focused. Most Tymora worship is done at small traveller's shrines, hoping for fortune or safety on a journey.

The tower of Luck in Waterdeep is unusual for Tymoran worship, it's the largest temple to Tymora in Faerun (and the only one that's remotely close is in Suzail) - part of the money for such a large institution comes from placing it in the noble quarter of town (the Sea Ward) and... not dissuading nobles that donate huge sums of money in the hope of it "buying" them fortune and luck in the future.

The other part comes from the temple sponsoring and supervising gambling houses in the city - most official gambling establishments have a resident Tymoran priest who blesses the proceedings, and is there to assure punters that the house is running a fair game, and not stacking the deck. There are non-sanctioned gambling houses in the city, and they often offer better returns on bets, but... they don't come with these assurances... so really if you go there you're making a different kind of gamble.

This relationship between the church and "sanctioned gambling establishments" might explain why, our of the extensive list of guilds in the city, there isn't a guild of gamblers or gambling houses.

As for Konsi herself, while she recognizes that gambling represents a form of worship to Tymora, she much more subscribes to the "good karma" theory of fortune and fate. Those who do good deeds will be smiled upon by Lady Luck, and their good deeds will be repaid in kind. She doesn't tend to go in for gambling games too much, because they tend to require a bit more calculation and mathematics than she's comfortable with, and thus her knowledge of these games is a little sub-par for the wishes of the church.

It's a fun religion, they even have a casino floor in the church itself where you can just hang out and play some chill cards.