First of, she's my girlfriend. A quick question, will she ask me to stop if I win an amount big enough to not just marry her but start a family? The truth is that some women act out of selfish interest, they advice you just so that the money used to take care of them will not run out.
I had a girl that told me about her first boyfriend, she left him all because of gambling, I too was an addict during that time but she did not know. What I have noticed about girls is that they do not want anything that waste money or take from someone than give. That is the reason you will see them not gambling at all, only few of them are gambling if compared with guys. If a girl love a guy, they can be honest, about gambling, I think it is honest for a girl to tell his boyfriend not to gamble again, they do not just say that, it is because they have had a boyfriend that had gambled before and was losing, or they see that gambling is taken from their boyfriend than given.