So , I killed her ..and I am wondering ...Should I of done so or should i of allowed her to capture me? 

There is more gameplay associated with surrendering than with killing her, with another area you wouldn't otherwise see, but if you want a 2h sword, I think hers was pretty sweet.  She does not play a major part in the story if you let her live, making one last appearance where you'll have to avoid killing her again.  Personally I found killing her at the ambush really hard except by forcing her to chase me into a small room where the archers couldn't hit me, so I don't think you're 'intended' to kill her there.  Obviously it's possible.

If you got captured, you'd get a short and pretty hilarious quest involving your companions. Anyway, you killed one mean bitch there - congratulations. That's all.

When are you talking about?

I guess I'll go back and let her capture me then to do the quest . thank you

I killed her because her face annoyed me.

Wait, are you guys talking about the giant fight at the end of your attempt to capture the queen? You can survive that? O.O

" Wait, are you guys talking about the giant fight at the end of your attempt to capture the queen? You can survive that? O.O "

" Wait, are you guys talking about the giant fight at the end of your attempt to capture the queen? You can survive that? O.O "

FUUU. I tried so many times, but never was able to. I guess I suck at Dragon Age.

I'm pretty sure that even if you defeat her, she shows up again at the Landsmeet. At least on the 360 version. It's how you get the Summer Sword twice. 
 
But yeah, the area after you get caught is arguably one of the more enjoyable parts of the game, especially if you're a rogue.  
 
edit: Yeah, according to the Summer Sword article on the Dragon Age wiki, if you kill her, loot her, then let her guards capture you, you can get the Summer Sword twice. Not sure how that works though, since you can't loot in the middle of combat. Either way, getting captured is the way to go.