The 19-year-old said that she feels "lucky" that she will working with Sharon Stone, Adrien Brody and Bette Midler.
Explaining the role, she told Star: "It's crazy, isn't it? It's called Sweet Baby Jesus and it's released next year. It's a comedy about a man named Joe who accompanies his pregnant girlfriend Mary to Bethlehem, where the villagers assume they are the second coming.
"I'm playing Mary and Sharon Stone plays my mum. Adrien Brody and Bette Midler are both in it too.
"I feel so lucky that the cast is so amazing. It's going to be a privilege to work with them. I had no idea things would take off so quickly."
Lott revealed that she has developed a passion for acting after starring in the US teen drama Fred: The Movie last year.
She said: "It was a light-hearted kids film, so that gave me a little taster. I loved it and wanted to get more involved.
"We'll see how this one goes. I don't know if the film will do well or not but it will be a great experience to work with so many amazing people and focus more on my acting."
Lott will start filming Sweet Baby Jesus in the next couple of months.