healeveryone | Timeline Notes

2003 - Rosalia is born. (Source: math)
2010 - Maria saves Rosalia from the orphanage fire. Rosalia is adopted soon after. (Source: artbook)
2012 - Cumberland College events. (Source: game) Sartre disappeared after this and probably ran off with Rosalia around then; she likely thought they were just moving to Mexico so her dad could focus on research while her brother worked on his education. In any case, they did live in Mexico and work on research following the Cumberland College incident.
2015 - Rosalia sends Maria a letter from Mexico. (Source: game)
2018 - Sartre dies in America. (Source: game) My guess is that this is within a few days of Rosalia's death, a week at most, due to the effects of the virus - he was already experiencing some of its worse symptoms when he killed her.
2020 - events of Trauma Team. (Source: developers)

Notes
- It states somewhere on the development blog that Trauma Team takes place two years after Under the Knife/Second Opinion and a year before Under the Knife 2 (therefore, 2020). Running this through Google Translate seems to confirm what I've heard. The rest of these dates are based off that.

- All artbook information comes from my possession of it (yay earning money) and a friend's understanding of Japanese. The artbook states that CR-S01 is adopted at age 9, enters med school at 12 (making him arguably even worse than Franziska von Karma what), and is 16 at the age of the Cumberland College incident.

- Other specifics: Maria mentions in Missing Girl that she received her letter from Rosalia five years before the game. CR-S01 states in the same conversation that the Cumberland College attack happened eight years before the game. Demons and Death proves Sartre died two years prior to the game--also presumably soon after Rosalia's time of death, because he was vomiting large amounts of blood at the time he killed her. It is established, however, that he had enough time to store his gun somewhere and get the suit he died in; he was also taking large amounts of antiviral drugs, including one dangerous unapproved one, though this could have occurred even while living with Rosalia due to the nature of his research.

- Rosalia is roughly fifteen at the time of her death, based on the following facts:
• The game takes place in the year 2020.
• Rosalia dies two years before the events of Trauma Team (2018).
• The Cumberland College incident took place eight years before Trauma Team, when S01 was 16 (year 2012).
• S01 was was 14 years old when Rosalia was adopted (year 2010). (Note that the artbook says 13, but the game says 14; I'm going with that S01 was really close to his birthday when Sartre found Rosalia, and passed his birthday shortly before she was actually adopted.)
• Maria saved Rosalia from the orphanage fire when Rosalia was 7; she was adopted soon after that, so Rosalia was also around 7 years old when she was adopted (year 2010).
=> Rosalia lived from roughly 2003-2018, making her about 15 years old at death.
As an aside, this means that S01 and Maria are both 24 years old (or that Maria is at most a year older) during Trauma Team - which is ridiculous, but realistic ages went out the window way back with the twelve-year-old med student.