First of all, set the time to the max which is 10 when you load up a server.We will be using Annie 2 of course, all you need is two people, if you dont have a friend just open another tab and enter the website then the server.(Multiplayer will be explained below) The main concept to killing the Female titan is to hook onto a part of her body and swing around her using gas. When her back is towards you, release the gas for a second to close in on her body. Hold down the attack button because you never know when you will be at her neck and release at the right moment. Dont go for the ankle because it is too risky and the female titan will kill you easily. Thats basically it, follow the steps and always be careful when coming close to her, after you see the number immediately run away as your blades will break instantly. Multiplayer is recommended as this WILL BE MORE FUN!!
Multiplayer Tips
1) Move in at the same time, if one player dies, the other needs to back off immediately so that humanity does not fail.
2) Best if there is verbal communication so that you can carry our step 1 easier.
3) After player 1 respawns, player 2 should continue to stand on a branch so that the player 1 can hook onto the female titan to do the steps above.
4) DO try to aim for the nape of the neck when shooting your hooks
5)This is something I found out recently, if you are not aiming the ankle, USE LOCK. I dont think this was ever done before.
Thats all for now

Proof that this works http://imgur.com/6WCFt6Y
Another method by Liduso(Solo) http://fenglee.com/forum/viewtopic.php?f=10&t=6744