Okay, let’s break this down logically. An unborn inside a person is an organism. A human being is an organism. Therefore, an unborn inside a person is a human being. Simple enough?
Sorry. Certainly I agree that this child is, and always was, a person, but your attempted logical syllogism is faulty. You can see this if you substitute the word "parasite" for "unborn":
Therefore
What you've got to show is that this 7-year-old girl, call her "Susie," who is a person, is the same person as the fetus inside of her mom 7 years and 5 months ago.
Clearly, if Fetus Susie's arm was ripped off, Susie would have been born without an arm, because --- well, whose arm was it? It wasn't her mother's arm, it was Susie's arm. There is a continuity between Fetus Susie and Newborn Susie and Seven-year-old Susie.
You've got to show why the law is wrong if it say, "Fetus Susie has the same 'personhood' status as parasite."