The influence of gambling can penetrate with her young age so better not to let this kind of activities be her hobby best to find alternative ways to be entertain or if she's into other means of making money better to lead her to other options like online selling or something that will keep her busy though depends on how you and your daughter will handle things all got their own opinions about this but the decision remains to both of you.
The greatest fear of this action is, "what if this girl becomes addicted? " Just what if? Then it's going to become a big problem for the girl in the future which she might exhibit some addictive behaviors that no man would want to risk getting married to an addict or even after the is married, what happens when she starts using her kids money to fulfill her gambling needs, that means her children will suffer it too. If you must let your kid gamble, it should be at the right age and also with a strict guidelines of not becoming addicted.