Great reaction, Sasha was the gang's netrunner before Kiwi, we are talking 2 or 3 years before Edgerunners, the job was simply to get some information from the Biotechnica server but when she saw the report about the medicine her mother was taking she couldn't resist and opened it, long story short, the medicine had very harmful side effects and despite this, biotechnica decided to turn a blind eye. Sasha uploads the file to a news channel, hoping to damage biotechnica in some way thus costing her her life. Another detail is that in the end you can see Main's hand shaking, it could be that this is where he began his path towards Cyberpsychosis. Now let's react to some l'arc en ciel anime songs!!
Dawid Podsiadlo also sang the main theme for Cyberpunk Phantom Liberty. I'd say react to it too but to be honest its something you should experience in the game itself. Reacting to it prior might take away from that incredible moment.
"There are no happy endings in night city." You brought it up at the end that it was her younger sister? Sadly no, that was Sasha's younger self, she was forced to grow up without her mother after she died, and she still carried that burden with her. The ending of her embracing her younger self was meant that she did it.. she got revenge for her younger self and her mother.