parry + hit was my strat for everything besides kayran and dragon on my first play through :P

I made a couple of Thangar Winter traps and they work great, they do damage and stun.

By far the safest and most foolproof method is to simply run in circles and Igni her to death. If you are a mage this goes pretty fast (you can get 41 dmg Ignis at lvl 7), but since there is very little speciaization at the level you can achieve the same effect with a Petri's philtre, the +4 sign damage armor from mysterious merchant, and a sword with moon runes.

Or if that sounds like too much trouble for your nonmage, you can still just run in circles and kill her with Igni, but it will take a couple minutes! :D

I also found a lot of success using Aard. Aard, attack twice, repeat, when out of Vigor run around a bit and regen it.

It is quite easy to kill if you run away form it, wait for it to charge then dodge. Supposedly it ran into something and stunned itself, attack its abdomen with your silver sword till it regains conciousness. Repeat as necessary.

edit: Same tactics works against the Arachas as well.

Quite often Yrden will only stun her for a second, so what i tend do know is Aard then strike for 2-3 hits, than Aard again as while it doesnt stun her it makes her stumble and interupts her attacks.

You can also let it charge and move out the way, but it seems to take forever to decide to charge.

Its a very unforgiving fight, like most of TW2 combat actually, make any mistake and it can be like rowing upstream without a paddle.

Wait till she drops her f@cking guard!

Just collect 20 of those traps that are lying about, lay them down in one spot and entice the queen to run over them.

Instant kill. No fight. No fuss.l

I just loaded up with grapeshot bombs, like 40 of them, taunted the queen going just inside the edge of the area where she turns around, lobbing as many grapeshot as I could, then retreat outside the boundry so she turns back around and starts to head off. After she goes far enough to give me a little distance, I ran back into the boundry area and repeated throwing the grapeshot, when she gets close to me, combat roll back out of the area and wait again. After about 4 to 6 runs, she'll be dead, never had to use my sword.

I find this quite challenging, but i love to die a lot.

I've tried couple of things, i guess my problem is i'm not very good at dodging, somehow i want to play pc games with keyboard, not controller. Anyway, i tried winter traps, dosen't stun her that much. I found out that attack from behind makes much more damage, but it's kind of hard to behind her. Once she stayed quite far away from me, once i run away, i throw like 20 bombs, then went to see her, she had like 30% health left, then i died. Have to keep practicing and also want to try that insectoid oil.

EDIT: Well finally. Traps and finished with Aerondight

What worked for me is what SlackerSupreme mentioned. Place a lot of snare traps in the same spot before destroying the last cocoon, then lure the endrega queen into that spot. 20+ snares kill it instantly. A bit gamey, but every other strategy ended with Geralt instant-KO'd by that giant bug.