My Sister Passed Away About 8 Years Ago From A

My sister passed away about 8 years ago from a ruptured aneurysm on her brain. She had a headache for a week. The day she passed...she was working at my dad's restaurant. Her friend stopped in to see how her headache was. My sister asked her to feel the back of her head since there was a lump. As the friend did that my sisters eyes rolled back and she collapsed. My dad called 911 and she was then sent by life flight. By the time I arrived to meet them at the hospital, she was already declared brain dead. I do understand the Monro Kelly theory and brain is a closed vault. Knowing this... was the lump her brain stem from the blood pushing against it? Also is this called a peduncle bleed? Thank you, Cindy