Thank-you for asking palisadesk - my theory comes from the sum of all the parts - Nicole lived in a very large building with many tenants and got on the elevator twice that day - one return trip from top to bottom and apparently a second trip from the top - she was not seen either time. Nothing was found from a struggle - not a sandal, towel or anything else she may have been carrying. If she was off to meet a friend that was waiting for her, I don't buy she suddenly may have veered off willingly to do something else or go with someone else without letting her waiting friend or mother know. At 9, you know that someone leaving you standing and waiting for nothing to happen would not be appreciated.
I believe her friend btw when she said she spoke to 'Nicole' through the intercom. I just don't think it was Nicole and the friend had no reason to think otherwise.
Who was the last known person to interact with Nicole? Who independently verified seeing Nicole 24 to 48 hours before her disappearance?
Who kept this case in the public eye all this time? Who made public pleas to find Nicole? Who didn't?
The answers and lack of them help form my theory - and all is jmo.