Scratch

TheGameMaster1231 wrote:

What I (and a bunch of other people) think is that Caroline brought Chell in for Take Your Daughter To Work Day and GLaDOS took her and adopted her. Then, when Chell grew up, she was used as a test subject.

There actually is a bit of proof of this. In one of the rooms in Portal 2, there is a room with all these science projects (most have to do with potatos) and one is this big potato growing up into the ceiling, and in the corner of the project, it says 'By Chell'

She wouldn't be saying "oh child" if that was true then.