She knows how to hunt the BA, and she knows things never went well when they rushed into a situation before. Regardless of whether the new group was there to be observed or not, Elayne and co. would have had no way of knowing they weren't going into a house stacked full of BA just from Hark's observations and Jaem's statement that all the lights were out but one. Elayne knows better than almost anyone else that if you run into a dangerous situation on one piece of information (which you yourself said even the sneakiest of men hadn't the faintest chance of safely obtaining), you risk everything.

I am NOT going to type a novel like you did, and you're free to disagree, but I think her actions there were ridiculous. With all the speculation you put into your post, answer me this: how exactly does a noble fulfill her duty to her people by getting herself caught by some of the evillest wenches around and then relying on her (idiotic- obv, because she's female) warder to know exactly how to get her back w/o killing her whole army that she needed to keep the city and her people from an idiot like Arymilla? Having healthy babies is NOT the same thing as being free and safe while having them.

Yes there were difficulties in whom to trust, but sheesh.