I'm actually a little happy that my twin sister recently stepped in a yellowjacket nest and got stung all over her body
Why would you be happy about that?
I am so tired of looking just like her, now people can tell us apart.
It is wrong to wish harm and enjoy it on someone because they look like you. You should go apologize to them and try to help them out while they recover.
Don't you think it's good to see the bright side of things?
Normally, yes I do.  However, there's nothing good to be found in the suffering of others, particularly when they're someone close to you.