In theory, yes, but really no. I mean it's like years ago when George Bush choked on the pretzel. In theory it could block your wind pipe for long enough for you to die, but in reality, your saliva would make it dissolve before you would actually die. Even if you passed out, your saliva will still eat away at that pretzel, so chances of you dying are slim to none. Well same goes with spit really, I mean choking to death on any liquid is nearly impossible. Even if her saliva made it all the way down her wind pipe to her lungs, it won't do anything. The best thing she can do is drink some water while this happens, the swallowing motion from her esophagus will help to displace the saliva in her wind pipe, and it will soothe her throat. So when she's doing this, don't feel useless, have a water bottle on hand or something. As odd as it sounds, my female friends feel that would be a romantic gesture (more specifically, being prepared for her).