Dana Hee was also the stunt double for Talisa Soto (Kitana) in MK1, this reinforcing the whole twin story. I have a theory that as soon as the fight began, Sonya realized she wasn't fighting Kitana.
Also, in MKA when Sonya fights Mileena, she mistakes her for Kitana
Sonya: 'Kitana!?'
Mileena: 'You Wish!'
This is never brought up however. Which to me seems a bit.....strange. They were obviously going for the Kitana/Mileena twin issue, yet it gets forgotten about as soon the fights over. Sonya neither checks nor confronts Kitana about someone who looks identical to her. Strange. Also Mileena is played by Dana Hee, who plays Siann in MKC