No she doesnt, there's no proof of her actual death, she creates a copy so that a sonya continues on in the adventure, she's likely still fighting the apotosis
To further prove my point, altough i highly doubt the relevance or even the neccesaity and character writing of sonya, she's still someone who's literally there from the beginning of the story, a character like that wouldn't just die offscreen
This series has dubious writing quality, but i doubt even torotoro would make such a cheap death
Not to mention that it still remains to be seen to what extent the decisions made during the adventure affect regardless of the route. Because I keep saying that no matter what, there has to be something more behind the options in certain dialogues where Luka can say something meaningless like dominating the world.
Also, reviewing recent comments, I don't understand why people are saying that the content of a third route may be released after the release of Act 3. Both in the trailer released too early in retrospect now that the final part will finally be released and throughout the main story and base outside of the collaboration. It´s made clear that a third route existed through the characters of Brinhild, Nero and Neris. The only characters that "at first" are always out of place in the events and that curiously, the rabbit doesn´t have the ability to "fix" despite that being his job. In addition to finally seeing the motivations behind those 2 above all.
Nero always helps in the adventure, but he always stays half-hearted in his help and it seems like he doesn't want to get "in a fraternity" with Luka's group, like... someone who doesn't want to get close because he knows that in the end there will only be blood.
While Neris, on the other hand, has practically taken care of "in principle" the biggest challenges of the original adventure to make Luka's group go faster in their journey... only for her to end up causing more problems, except in the battle with the 6-tails, the only battle where in fact... the only thing she did was just speed things up.
Since remember that her intervention in both the battle with Angel Killer and during the end of the conflict on the continent, was because Nero asked her to help in the battle that she help but she had no intention of intervening. Which would make one think that both brothers, despite having the same objective, their methods are like the sun and the moon, Nero supporting but always putting a line of mystery and separation, while Neris supports from the shadows and apparently she wants to "spend some time with Luka". But with the end of act 2 and knowing that it´s from the original Luka himself that they receive orders... then what is the prime Luka planning...
Also... since Nero always respected Luka Prime and even "sounded" friendlier, the theory that Nero and Neris were orphaned and raised by the knights I think has lost strength and at most they were only trained by them. Neris by Alma Elma and Granberia and Nero by Tamamo and Erubetie.
Which... again, if then Neris' attraction to Luka is true because he is the only man with the exception of his brother, the strongest and most profitable man in humanity even for his time... then Neris literally applied the... "I'm not going to take mom's food away, so I'm going for my own"...
In fact, I liked more the original idea that this attraction was because she "fell in love" with the legend that was her father when she was an orphan and that was her reason, but if the prime is alive and kicking... then it's more... crazy, but not weird in the standards of the MGQP world.