Every little harassment outside their home, someone will surely show up and be a knight in shining armour.
They didn't like these, despite the fact that it's like a help.
When they looked at Diana, their minds got unsettled. They don't like that someone knew her and might come to claim her later.
This nailed fear into their heart. No matter the help they received, it can't match their attraction to the girl that they went through a lot to make her become alive today.
When the girls return from school and run to hug them, the pure parents warmth felt different.
Diana noticed this as well, since she's a sharp girl. She will look up at them with her confused eyes, while sometimes, she will catch the distance in their expression.
Instead of causing ruckus, she will smile at them and ask if they are okay. Her cute innocent eyes staring at them with such confusion will melt them.