Without you she would definitely going into gambling, so that dont make you a bad father. The question you should be asking yourself right now is how come she got into gambling. Have she at any point see you gambling and then pick interest?
After figuring all of these then you will know your influence towards her. If she is gambling by her own will, its all good but if she is doing it because she watched you do it then you might have influenced her wrongly at that tender age.
You are asking the right questions, if she started gambling because she saw him gambling then that makes him a bad parent this is the unfiltered Truth. Even if she eventually learns how to gamble later on from peers or wherever at least she's grown enough to handle her emotions but at such a young it's bad for her mental health. If she gets obsessed with this it would be hard for her to focus on academics