This is rare, but I was actually in your exact situation. My mother left (she didn't pass away, but she left the country and signed guardianship to her sister -my aunt) and I moved in with my aunt and uncle and their 3 children. I was 1 year older than their oldest daughter, and through highschool I had similar expectations set on me as my cousins. It wasn't until I was 15 and I began working in order to save for my first car that the reality hit. I worked for my own first car, she was given a brand new hybrid no strings attached. They paid for her college education 100% and I had several conversations with them about cosigning a loan I would pay back (which is ultimately what happened with $1500 out of over $30k of student debt). Also once we graduated college, they gave her a rent free apartment live on main street downtown. She lived there for two years rent free after college. I was sent a 1 box full of all my belongings just 1 month after moving away to college (dorm life, my permanent residence was their home states away). My aunt said she needed the space and what I had left behind was too much to store there.

All this to say, I understand. You are not TA.