The actress was cast in the ITV1 soap earlier in the summer and Rachel makes her first appearance on screen in tonight's episode.
Rachel's debut sees her storm round to the Dingles' home in a rage, accusing young Samson of bullying her niece Amelia.
Speaking to ITV Calendar about her first scenes, Oaten commented: "For me, barging into the Dingles' house and giving them what for was really bizarre, but that's the joy of playing Rachel - she's got no connection to any of them, so she doesn't know that the Dingles aren't really a family to be messed with. She really doesn't care - she just goes in there all hell blazing and gives them a piece of her mind."
However, she continued: "I think there's a very lonely side to Rachel inside that I'd like to explore more, and I think that will come out as the weeks go on. She's got quite a quirky sense of humour and I think the writers might have seen that in me and have started to pick up on the fact that I'm quite daft in the head as a person, as Gemma!"
Oaten added that she is thrilled by the news that her character has family members arriving in the show.
She said: "I come in with my niece tonight. There is a nephew that is coming in too, and there's going to be an extended family that I haven't heard too much about yet, so I'm really excited to see who I'm joined by in the coming months. It'll be great!"
Emmerdale continues tonight at 7pm on ITV1.
> Emmerdale casts feisty newcomer Rachel
> Read our full spoiler for Rachel's first episode of Emmerdale
> Read more Emmerdale spoilers and news