^^^ Took the words right out of my mouth.
Believe me when I say this....
Spoiler:
If an average teenager's parent was killed, there's a chance that they wouldn't find the strength to try to cheer their other parent up. All that "comforting the other parent out of kindness and respect" will only happen if...
1. Unbelievable anime characters came to life.
2. The character whose parent died WASN'T an adolescent teenager. That's an important factor right there, since most teenagers haven't seen enough death in their life to get used to it, especially if it's a parent who died.
Trust me, one of my friends did the same thing when he found out his dad had cancer. It didn't even take death to force some tears out of him.
Bt still, I agree that Shirley was using her father's death as an excuse to get some love from Lelouch.
I don't hate her for it though.