This is for beating Laura in Chapter 5. You can easily beat her using your surroundings. You want to use fire against her. There are two explosive barrels and 2 torches you can use as well as some switches that will shoot fire out of areas on the map. If you have a fully upgraded Harpoon bolt(Which is unlikely in your 1st playthrough) that will also light her on fire. Keep lighting her on fire until she dies.