Viewers were shocked to see Gennie's demise which occurred after a dramatic car chase between Gennie and Cameron, along with Debbie Dingle.
The pair were chasing Gennie after discovering she had overheard Cameron confess to killing Carl King - but unbeknown to them Gennie also recorded the revelation on a Dictaphone.
Speaking to This Morning on Friday, Sian said: "There's a Dictaphone that they haven't found, where did the Dictaphone go?
"I know as much as you, but I wonder whether Gennie might actually be the one to bring Cameron down in the end anyway, hopefully."
The actress announced earlier this year that she was set to leave Emmerdale and admitted she was pleased with the dramatic exit the soap's writer's had given her.
"I wanted something memorable and something to get my teeth into and I didn't want to go away in a taxi," she said.
Its closure for me and it's the best possible way.
"When there is a serial killer on the loose you kind of think 'ok, I probably know which way I'm gonna go'.
"Five years was amazing, I have made the best friends and made the most amazing memories and now I can move on and it's a clean break."
And Sian said she was overwhelmed by the amount of support fans of the programme have shown her following her character's untimely death.
"Twitter went insane. I'm still going through it all but thank you to everybody for their lovely messages.
"People have been really lovely, Gennie and Nikhil have been very popular I believe and that was really nice.
"There's been a lot of devastation, I felt like Take That were splitting up or something. People have been really emotional about it."