Technically abstinence would fall under morals, but obviously the girl meant that it's the morally just or correct thing to do, like as if sex before marriage was comparable to kicking homeless people. And therefore, she is an idiot and you really really really should have /faceplamed and told her she was straight up.
With that said I think not having sex before marriage is a really cool thing, but it's not for me.
I think everyone should live by a moral code, except when those moral codes differ from mine, if that's the case than you might as well be a serial killer.