we don't know how open or close you are to her. or how well you know her, or how she is. let's put it this way, if they are headstrong, and you are just taking pleasure in poking their sandcastles in air, then there is no point. believe me, it will make no difference to her what you say.
if she is really earnest about taking good photos, then you can put it nicely to her. the worst way possible to convey your feelings is to sneer and then say that you have seen better photographs. one way of doing it is to show her many beautiful photos, without saying anything. if she asks more, then you can elaborate about how to go about doing it.
if you think about it, essentially if she takes a night shot handheld with iso 1600, it will still be of better quality with pns camera.
give it some time, we've all been through the stage where we looked at cleaner shots from dslr and go WA IQ SO GOOD. after a while when you keep seeing better composed shots, etc.. (assuming that you DO care about composition) then that unrequired awe will fade away.
there are many ways to go about doing things. whether right or wrong, really starts with one's attitude and intentions. are you looking to be a office photography guru? or are you concerned about your colleague's improper approach to photography? you have to ask yourslef. if it is the former, then you need to reflect upon yourself, that is my feeling. there are better valued things in life to pursue then to gain a following of admirers, etc.
i do consider an audience when i shoot, but i feel happy when i shoot. to be honest, no one believes me when i tell them that i would be just as happy without a camera, sometimes the camera is just an excuse to be there, witnessing the beautiful light, remembering the most briliant moment of the day that always changes.
someone here once said that if you can't smile when you shoot, or when you partake in photography as a hobby, then you should think about where you've gone wrong. i wholly agree with this.