Peltz is best known for roles in The Last Airbender and Transformers 4, and like her fiance, is from a well-known family.
Her father Nelson is an American billionaire businessman, while her mother Claudia is a former model turned stay-at-home mum.
The couple have eight children, and Nelson has another two children from another marriage.
Peltz has one sister and six brothers, including actor Will Peltz, who starred in Netflix's Sierra Burgess Is A Loser.
Another of her brothers, Brad, plays ice hockey for the Ottawa Senators, while the other Peltz children have stayed out of the public eye.
Brooklyn Beckham revealed in an Instagram post last month that he'd asked his "soulmate" to marry him.
And the couple have shared some glimpses of her engagement ring, which the Sun reports cost £250,000 - around $488,000.
An insider told the paper that the Beckhams have given their blessing to the marriage.
"It's a very exciting time for the whole family and after a few previous rocky relationships, they think Brooklyn has landed on his feet."