if so,here is how you kill her.You see the cut-scene where it shows the giant egg fall?run to it as fast as you can and throw it at her,then hit her with everything you got.
You have to hurry,though.If you take too long the egg will break and more little spiders will hatch.
Find your stratagey.
How do you throw the egg all I'm able to do is roll the dumb thing around
while rolling it there is a keystroke to slam it foreward. I use a controller so for me its right trigger, but you might need to check your key mapping in the start menu.