From what I can see, this type of story has two outcomes for the MC to survive to adulthood
1. Dietrich’s cold heart is completely melted and he simply cannot bring himself to kill her
2. MC somehow becomes far stronger, to the point that she can defend herself from Dietrich’s betrayal and successfully run away
I’m leaning towards the first possibility but the second is very plausible. Perhaps there’s more possibilities that I’m not considering as well