nighty night bitch
It's true that the mission is pretty tough, but only if you make it that way. When I played that mission, I thought it be funny to tranqulize her, so no shit, I did. So I moved her into some tall grass and noticed that she was saying something in her sleep. She really is a freak about Snake cause the shit coming out of her mouth would of made Michael Jackson shiver.
To wake her up, you have to go to first aid and pull it out of her with your knife. Atleast when she's out, you dont have to feed her to much, and its easier to keep her out of danger.