I always felt happy that my sister isn't a guy.
Why would that be a good thing for you?
It's a relief to know that I won't have a brother like her.
It's wrong to judge people based on their gender, so you should accept your siblings for who they are.  You would love your brother just as much as your sister if things had turned out differently.
I don't want a brother like her, she's a jerk.
I get that, like I was saying you shouldn't judge people just based on gender. Regardless of being male or female you can have your own personality. It's wrong to think that gender dictates that.