Here's the problem. Even in modern times, in a generally progressive atmosphere, there's still a culture of shame imposed on victims of sexual assault. What the hell for? Sexual assault victims don't ask for it, they're not leading their rapists on, but there's still this culture that makes victims afraid to confront the perpetrators for fear of being, what, blamed for her own rape? I don't care if you think sexual assault is overreported, underreported, true or false. A culture that makes it so a victim is afraid to get help because of fear or shame, that's just plain f'd up.
Had she received some kind of support in the immediate aftermath, even just assurances that it's not her fault, she's not to blame, there's no shame in being a victim, she might have felt confident enough to seek out the right treatment or therapy from the start. Not let shame of what happened weigh down on her for so long it came to this.
This entire discussion is predicated on a false dilemma-- euthanasia's not the issue here, it's that being the victim of sexual assault carries such an aura of disgrace as to make suicide seem a preferable alternative to speaking up.