Yeah, no, I don't feel like she needs to feel guilty about murdering her parents. Going just by the flashback, despite being a vampire and a true ancestor, she never attacked anyone or even sucked blood beyond the one time she clamped on her friend's finger when she awakened.
But someone in the village called in a hit squad that, without hesitation, stabbed her father to reveal her nature; her parents and even siblings then immediately disowned her and were going to let the church murder their daughter, whom they'd raised for 10+ years.
They say you should cut toxic people out of your life, even if they're family; all she did was take it a bit literally.