Actress Mackenzie Foy has a small but pivotal role in the upcoming final Twilight film: She's Bella and Edward's daughter.

Photos of the 11-year-old actress in character as Renesmee Cullen posted by Entertainment Weekly show her being guarded by her vampire parents.

Here are five things to know about the Twilight saga's youngest addition. Be warned: There might be a spoiler or two here.

The Twilight cast had to behave around Foy.

This will be the fifth film for the Twilight actors, so they're probably quite comfortable around each other. But they had to try being on their best behavior around 11-year-old Foy. Robert Pattinson (i.e. Edward Cullen) told Entertainment Weekly that Foy had a swear jar and made about $850.

We're all around the same age, and we're really not polite to each other anymore, Pattison told Entertainment Weekly. You'd have to tone it down when Mackenzie was around.

This is actually Foy's second Twilight film.

Foy had a so-brief-you-could-sneeze-and-miss-it part in Twilight: Breaking Dawn -- Part 1. She appeared in a flash-forward vision Jacob Black had toward the end of the film.

Her character's name is unusual, but there's an explanation.

Bella and Edward's daughter's name in the Twilight books is Renesmee Carlie Cullen. Her first name is an amalgamation of both her grandmothers' names, Renée (Bella's mom) and Esme (Edward's adoptive mother). Her middle name is a portmanteau of her grandfathers' names, Charlie (Bella's dad) and Carlisle (Edward's adoptive dad).

Foy has mostly done television.

Foy appeared in one episode of Til Death, Flash Forward and Hawaii Five-O before we saw her in Breaking Dawn: Part 1. She also appeared in an episode of the kid-oriented series R.L. Stine's The Haunting Hour. Her film resume is building up, though. Her upcoming movies include Plastic Jesus, which stars Hilarie Burton (One Tree Hill), and The Warren Files, which stars Patrick Wilson (A Gifted Man) and Vera Farmiga (Up in the Air).

Her Breaking Dawn character ends up with Jacob Black.

Don't worry, it's not as dirty as it sounds. In the Twilight books, imprinting is a love-at-first-sight thing that happens among Bella's Native American buddies. Some of Jacob's friends already imprinted by the time he did. Imprinting happens suddenly and without warning and signals the start of a deep and lasting love. It usually happens between older people, so there's romance right off the bat, but since Jacob imprints on Renesmee when he first sees her as a baby, he'll be more of a brotherly, friendly figure to her until she's more mature. If it all sounds too far-fetched, just remember, it's fiction!

READ ALSO: 'Does This Baby Make Me Look Straight' Author Dan Bucatinsky Is Just Another Dad (Only Funnier Than You)