Alright let's look at this from a real life point of view...
Would someone really want to jump if they felt the person they loved denied them? I mean, obviously she had a connection with the MC, but if this were real life, would they take that extreme step instead of just going about living their lives?
If what happened, happened, she obviously took the more extreme solution and completely felt unloved and inferior, and was desperate enough to not feel any more pain in her life; from her father, mother, people at school, the MC, whoever else. Was she that much at the end of her chain that the MC was her other true shot at love and happiness, to the point where if he denied her, she'd take the plunge?
Does her decision mirror real life at all and the possibility of what could or would happen?
Yes, the rate of suicide among trans youth is appalling. Without feeling someone is in their corner, many choose to end the pain that way. Many have called suicide a permanent solution to a temporary problem, but the problem looks pretty permanent to trans youth in crisis.
From an article in Forbes:
The survey is based on the experiences of nearly 35,000 LGBTQ youth, ages 13–24 across the United States, from October to December 2020, according to Green.
An alarming 42% of LGBTQ youth seriously considered attempting suicide in the past year. That number includes more than half of transgender and nonbinary youth who took part in the survey. For white youth, 12% attempted suicide, compared to 31% of Native/Indigenous youth, 21% of Black youth, 21% of multiracial youth, 18% of Latinx youth, and 12% of Asian/Pacific Islander youth.
That just counts those who attempted or considered it, not those who actually died. Another study said between 22 and 43% of trans individuals have attempted suicide at some point in their lives. Trans individuals are 2x more likely to attempt suicide than those who are Lesbian, Gay, or Bisexual.
So yeah, Nea's bad ending is all too common.