While Mary made her little proclamtion to herself, she never thought that someone might be listening. Now, it was true that Lucy had never followed her sister, but by a stroke of luck, she was by an air vent in the wall. This vent just happened to be connected to one in Mary's room. Through it, Lucy heard everything her little sister said. Now, Mary may have had determination, but she was also still a child, she didn't think things through.

Lucy, on the other hand did.

It was definetly true that Lucy was mean, selfish, gluttonous with some socipathic tenedencies, but she was not stupid. She was fully aware beforehand that her actions as of late would put her little sister over the edge and onto her breaking limit. That was what Lucy wanted. When she orginally confronted Mary for the cookies, and offered her that choice of helping her either eat the family or some random kids, she had had a second goal in mind. If Mary helped her with the family, she would've let her little sister get big again. Why? Because big sisters like to teach their little sisters.

If Mary had helped her, Lucy would've taken her under her flabby arm, taught her, molded her so she could reach her full fatty potintial. What was the point of gaining all this weight if one didn't push its limits?! Mary was weak in Lucy's eyes, unwilling to truly gain at other's expenses. By helping her, Mary would've gone done the road to realize her truly large destiny.

But when Mary had chosen to get some random kids, like she did, she failed Lucy's test. Mary was willing, at least at the time, to get rid of people she didn't know, but was unwilling to if she knew them. That was all Lucy needed to make up her mind. Mary would always be weak by Lucy's definition. And by that standard, Lucy never expected Mary to swear revenge. But, hey, people were full of surprises.

Lucy's mind was already working to foil her little sister, who most likely hadn't even come up with a true plan yet.

'What're my options?' Lucy thought to herself.

Considering Mary's anger, it would easy to manipulate the little girl. All Lucy would have to do, is allow her to gain weight, put up a 'perfect-big-sister' act combined with a fake 180 degree personality change and infuriate Mary all the while.

This simple plan would accomplish multiple things on several fronts. First, by allowing Mary to gain weight, the little girl would be emboldened by it, beliveing that she was doing things without Lucy being able to stop her. Second, with her presenting a new attitude, she'd be able to get in good graces with her parents. Now you see, Lucy's parents turned a blind eye to her activities, as their daughter had yet to do something to adversely affect the household. Therefore they were on neutral ground with her. With Lucy acting all goody-two-shoes, her parents would eat it up like the chumps they were. Also, her attitude would have an affect on Mary, who would grow further fustrated and angry. Eventually, when Mary felt that she was big enough, she would try to attack Lucy, who at that point would act like the victim. Their parent would step in, the situation would go out of control and in the fray Lucy could...dispose of Mary. Lucy's now none squirming stomach gurgled as she thought of such a huge meal.

Or Lucy could simply eat Mary tonight. She'd wait for her sister to either fall asleep or let her guard down. They she'd swoop in, gooble the helpless girl up. She'd then call her parents and tell them Mary ran away, upset that she couldn't eat as much as she wanted anymore. That whole scenario would make sense and all the evidence of Mary's death would be in Lucy's belly and eventually down the drain.