it would depend on how passionate she is about it.
i'm catholic.
i nearly always wear the rosary beads my great grandmother gave me for my holy communion
i have a couple of religious related tattoos
i say a little prayer now and again
i only go to church/chapel once in a blue moon...usually for family related events
the only time i really talk about religion is usually when people ask me why i wear the rosary beads.
if she was just like yeah, i don't believe in anything

and it wasn't serious to her like that, then yes.
but if she was one of those ones that gets in the argument and brow beating about it then shed get the

treatment.
i don't push anything religious on anybody, i feel people should believe what they believe if it helps them go about life in an easier way.
unless they chose to get into these debates/arguments with these people then i don't think you should be brown beaten or ridiculed for your faith.
if i was to marry or be serious with a woman who was an athiest she would still have to come to all the catholic related things like christenings, first communions, confirmations etc that my family would be involved in.
theres been plenty of reasons why i haven't got serious with certain women or why i won't see her anymore but religion hasn't been one of those things...yet.