Reese-Williams revealed that her character, who is engaged to factory partner Nikhil Sharma (Rik Makarem), will go into labour on the Dales.
"I'm not allowed to say too much about how dramatic it is, but it's outside. And it all happens very quickly," she told the Daily Star newspaper.
The actress also joked: "Apparently you sound like a cow when you're doing it, so I'm just going to moo a bit and it will be fine."
However, the star also admitted that she is "nervous" about filming the scenes, adding: "I've been watching a lot of One Born Every Minute for tips."
Speaking more generally about Gennie's pregnancy storyline, she reflected: "This has put me off having kids. This is enough for me, at least I can take the bump off and give the baby back.
"I did get attached to it though, it was like walking around with a cushion all day, I kept hugging it.
"And my body thought I was pregnant, it was really weird. I was eating more and not moving. I need to go on a post-baby diet!"
Jennie McAlpine performed soap's first live birth as Fiz Brown for Coronation Street's 50th anniversary, and EastEnders star Danielle Harold became the second actress to take on the challenge in a special segment of Billy Mitchell's Olympic episode.
> Emmerdale live episode is exciting, says Nikhil actor Rik Makarem
> Read the latest news about Emmerdale's 40th anniversary here