Going to an area Rand has just taken over has happened before. When Sammael and Illian fell Graendal's own point of view showed that she went there to see what she could pick up and to cover any tracks she may have left. She specifically commented on there being Asha'man who she calls pups but dangerous pups and Rand popping in and out.

So it seems clear that Graendal is not a coward. She will take chances with her personal safety if she judges the payoff to be worth the risk.

So what was the risk? Yes Rand is there and there are Aes Sedai and Asmodean who as far as Granedal knows is at full strenght. The Aes Sedai on their own are not a big threat, unless there are a large group of them together she can handle two or three if it comes to a fight. We generally don't see sisters or wiseones going through the palaces in large groups, its more like two or three at a time.

Even if she comes on say 10 Wise Ones together they won't know who she is unless she tells them or does something stupid to betray herself. Mostly she will be taken for some noble and there would be quite a few of them around the palace. Inverting her weaves and hiding her ability to channell she can be holding the sourse ready to strike and none of them would detect her.

The main risk is if she runs into Asmodean who will recognise her and Rand who may or may not recognise her. If they are together and she is spotted she is in trouble but I would guess that Graendal's plan would be to travel away asap. When she sees Asmodean on his own she panics and strikes to kill and not knowing that he is shielded she succeeds then gets out of town before anyone notices.

So the risk is low to moderate, what is the gain? Firsly she may or may not have left clues there to her own involvment with Rahvin. If she has she will want to cover her tracks she does not want Rand comming after her.

Even if she has not left any traces of herself she would probably want to check out if Rahvin left any intersting toys around. Perhaps he had found some ter'angreal she could use, perhaps he might even have an angreal that she could use. Getting her hands on them if there are any is worth a little risk.

Lastly she no doubt wanted to find out what the hell happened. Rand was suppost to go after Sammael in Illian. Suddenly he has gone off in the wrong direction and killed Rahvin. Graendal would want to know what happened? Did Rand get wind of their plan? did one of the others betray them. Lanfear has just dissapeared, what if she betrayed them all. Worse what if Rand caught her, got the info of the plot from her before killing her and was now cleaning house.

As someone in on the plan Granedal is on any potential hitlist. Yes she had extensive Darkfriend contacts but this is a clear and present danger to her personal survival and it takes time to get reports. Faced with the very real chance that Rand might just show up at her doorstep in the next few hours I think Granedal would want to go check out things in person while keeping under the radar so to speak.