Talk to her, and if she offers you an explanation about the jackpot select 'NO'.
In the west there's this particular bunny girl standing next to that big pillar filled with golden coins. Enter the VIP part of the second casino (it's the part with the roulette tables). Nope, turns out there is a pretty simple way to win the jackpot. This side quest is driving players crazy because it's based on pure luck. As you might know there is a certain side quest that requires you to win the roulette jackpot at the second casino.