[quote=@Techspert]
<Snipped quote by Yatagarasu>

Just... What [i]can[/i] I do? How can I ever be a good sister, or a useful person like [i]this?[/i]
[/quote]

Well, from my talk with her, Stella seems to think you're a pretty good sister. 
*Sighs*
But still, you're young. There's no need to worry about what kind of person you'll be, and being "useful" isn't necessarily a good goal to have, in my opinion. You have time. More than that, I'm doing my best to try to give you the freedom to learn and grow into whatever kind of person you want. I'm not doing a good enough job, but I'll do whatever I can for you four.