If she never found out whose sperm it was she would be completely happy with the outcome. It was “anonymous” until it wasn’t.
How can one suffer a “violent act” and not know about it for 20 years? I think you’re stretching the definition of “violent” rather far.
The “penetration” and the entire procedure was completely consensual. That’s how it’s “not rape”. Rape is a violent sexual act. Pregnancy is often an outcome but it isn’t the goal.
This asshole injected himself into her family which is a huge betrayal of trust. Just not rape.