Who Is MILA?

Let's dig into the details of our main character, Mila. Developing her character and personality is essential to the film opening. 

Basics:
Name: Mila
Age: 14
Family: Has a younger sister, Lenny. Two parents, deceased, but alive at the time of flashbacks. Had two amazing parents, was an only child. 
Current situation: Caretaker of Lenny, they're surviving together in a makeshift camp on the beach. Lives alone on the beach, trying to survive through isolation and the fears of being alone in an empty world. 

Physical and practical details:
Build and look: Very lean, strong from constant movement and work. Hair is usually tied back in a bun, ponytail, or braids that leaves it out of the way when she's working. Dirties clothes, wrinkled and layered. 
Tools: Small backpack, a small folding knife, an old blanket (in her tent), a family photo.
Skills: Foraging, basic first aid, making shelter, reading simple maps, starting a fire. She has very nimble fingers. 

Personality and character traits:
Core trait: Protective and resourceful. She is very resourceful. Mila is very protective of Lenny and feels responsible for her. Her care for Lenny determines her every choice. She's smart and knows how to solve problems. 
Emotional character: Very cold and distant to strangers in fear of transmission of disease, fiercely loyal to those who have proven her trust. She acts tough, especially in front of Lenny, and hides all fear.  Was a joyful and outgoing child, thrived on social environments. Isolation has kept her from her past lightness and shows how she maturely handles hardships. 
Habits: A habit of scanning the horizon and listening for people or animals, hoping for signs of life near her. She likes to retie her hair often, as it helps her think and concentrate. 
Moral values: Very emphatic towards human needs. She's always willing to sacrifice for Lenny. 

Backstory:
Pre-apocalyptic life: Grew up in a small city with loving parents who taught Mila what she knows now. She was young child with bright future ahead of her. Mila was smart and popular in school, she had a near-perfect life. She learned that family was important, and that she needed to help take care of Lenny. 
Survival: When the disease got to her parents, she knew she had to protect Lenny and run away. Mila became the adult in the situation and took Lenny far away from people. After her parents sent her away to be safe, she learned to ration her food, scavenge for resources, and improvise when needed. 

*EDIT: made strikethrough changes because some of her characteristics don't apply anymore.