Chapter 7 located after the 3 security checkpoints. You enter the Mainframe room. Turn the shaft to the left located on the controls to the right of the shaft. Go left in the maintenance shaft and follow the video from there
Go back behind the long rock structure in the back. Shoot the lady with the Plasma Cutter until she disappears. Hit the Marker with the Plasma Cutter. You will hear a bunch of screaming reload wait until you see the lady. Hit her with the force gun 3 times. She and the little creatures will disappear, shoot the marker again. Rinse and repeat. Every time you make her disappear the little creatures drop ammo and health.