Well there is no difference to gamble any gender are allowed.. and they are just looking for fun like other girls are playing and gamble in casino.. they are just few here in my country but when i was asking them they are just halving fun.. this is the main reason they say..
Visiting physical casino must be totally different experience from online gambling. Girls must love physical casinos as they might find it fun filled, but interestingly you need not to gamble by risking your own money to have fun in casino, just watching other gamblers itself will be entertaining you. But, online gambling needs total different approach, that may be a reason girls do not involve within it actively compared to men.