My Wife entered through Chicago with her K1 Visa. It was very pleasant. besides the long line, the process was easy. You can accompany your fiancé through the process if you choose. There is no need to split up. I went first and the officer checked me in. He then called her up to the counter. She just needed to hand the packet and her passport to the officer. The officer that we encountered simply opened the packet, sifted through all of the paper work, asked my then fiancé if she was aware that she needed to marry within 90 day. She answered " Yes". He then stamped her Visa, and said "Welcome to the United States" and we were through.