Beginning Of Planning for Thriller Opening

Today, Joelle Riley and I began to brainstorm ideas for our thriller opening. 
The narrative took a while to come together in our minds, but once we started to get our ideas down, things started to happen. 
We began with a basic thriller brainstorm and wrote down ideas for the character's names and their backstories. To the right is a brainstorm of our initial ideas.

Our main character is going to be played by Alice Malyon, she's a friend of Joelle's who goes to Inspire Academy which is an acting workshop. The main character is called Jasper Wynne. 
All throughout Jasper's life, she has struggled with her anger issues. The stem of this problem occurred from her father being absent for the majority of her childhood. This changed her into deeply sad and angry person from a very young age.
At the age of 13, Jasper's mother died. The only real parental figure she had died when she was very young.  
Jasper's now 18, it's been five years since her mother passed and she's going to regular therapy session with her therapist, Benjamin Winters - who will be being played by George Bartram as he's an experienced actor.

The scene begins with the pair mid-conversation. Benjamin will ask questions that trigger thoughts in Jasper's mind. This will be portrayed through flashbacks and cuts between the past and the present. 
As the scene progresses, the audience will subtly become more and more aware of the actions that took place when Jasper was 13, the thoughts that haunt her, and have done for five years. 
There'll be a flashback to an argument Jasper and her mother had five years ago. An argument at the top of the stairs.  The argument is heated but the specific nature of the conversation cannot be heard. The argument builds and Jasper's anger overrides her. She pushes her mum down the stairs, killing her. There will then be a cut to the bottom of the stairs, where Jasper's mother lies dead.
However, Dr Winters knows only that her mother is dead, not the cause. This will add to the atmosphere as it's a secret that she has told no-one.