From “The Torah: A Women’s Commentary,” it’s noted that Rebekah takes on a very active role in the story. She is the one doing most of the things, starting in Genesis 24:18.
“Drink, my Lord”
She lowers her jar
She lets him drink
She offers to water the camels
Then she empties the jar
She runs back to the well
She draws for the camels
In verse 21, it says the servant stood silently and wondered.
After he adorns her with gold and asks her identity, she invites him to her family home
She makes the decision to go with the servant
All this to say that Rebekah is not a character that passively has things happen to her. She is a character that is actively involved as well.
She is a true participant in the story.