Responsive: SISTERS Idea generation

So once I studied the brief I began generating ideas. The first thing that hits my mind when I think of the word sisters is a biological bond between two females. Does it have to be biological? Not necessarily, some times girls call each other sisters as an act of friendship, same as the expression "brother from another mother". However the exploration onto the definition of the word sisters was pretty fruitless to me. It did not give me any further ideas. Then I thought about what sisters do. I wouldn't know because I do not have a sister, but I do however have a brother, and sisters are non the less SIBLINGS. This term is more broad and gave me more ideas to work with. Definition of sibling in English:
noun
Each of two or more children or offspring having one or both parents in common; a brother or sister.
When I think of siblings the words that came to my mind were- sibling rivalry, fighting between siblings, parents, growing up with siblings,childhood, special bond, blood thicker than water. The one I went with was fighting between siblings, because this triggered a lot of memories about how I used to fight with my brother when we were kids. So since the theme of the competition determined that the main characters have to be sisters, I thought about when do sisters fight. The first thing that came to my mind was when they borrow each others stuff.

So essentially, sisters are like built in friends. But with the major familiarity usually comes great annoyance. Sisters usually fight so well because they are too much alike, and in psychology it is often times pointed out that the flaws of other people usually annoy you only because subconsciously you recognize those flaw in yourself. I usually get along with people pretty well, but if I dislike a person for no reason I ask myself why, and usually the flaws that annoy me the most are in fact the same flaws I posses. 

So the first idea that came to my mind after researching this, was sisters stealing each others clothing, for example jeans. A sister steals a pair of jeans, dances around in it and accidentally rips it. But the problem I ran into was how would I make it loop? Perhaps she tries to sow the jeans together and puts it back into place and then the other sister without the prior knowledge puts the jeans on. But then how would I loop it back to the other sister again? The object would have to be something in common because with the loop demand comes symmetry in the narrative. So what if they borrowed a thing from each other? That would be hard to illustrate that they are borrowing and not stealing, and stealing would not make sense in family friendly theme. Then I thought what do children/ teenagers hate that they would have in common- long family gatherings, parents lecturing and LONG CAR DRIVES! This idea really stuck with me for some reason, so I just ran with it. Sisters annoying each other on a long car drive, that is what I am going to animate!