The body disposal would need to have been completed before 8:45 on 9/11. No way getting in/out lower Manhattan with a body, and back after the first crash. City was paralyzed.
Murderer didn’t know planes would crash, so would have needed to just get lucky with driving to NJ (or other) with a body & knowing an excellent place for disposing. Also murderer would have needed good access to a private car garage so not dragging a body out in public.
There’s a chance she went to a suburb willingly, in a car, the night before and met her fate. Murderer got lucky, and her body disposed & never found.
Having lived near her, worked near her home, shopped at C21 often, I don’t see her shopping trip as unusual. C21 is an impulse-but shop, good return policy esp if you live right by the shop. It opened very very early - you could shop before work so maybe it opened at 7:45 or 8am. People were in there shopping when first plane crashed at 8:46.
She might have spent night with a person who worked in towers and perished which is why no one came forward. She could have been on way to C21 to return, visit friends office in tower (people did that) or go home - many reasons she could have been inside towers, or gone inside to help.
IMO it is so likely she was in that area, at that time. More likely than meeting a serial killer.