Scott: Jackson is your adopted brother and, although you aren't really related, you act as if you are and when Jackson found out about you and Scott he moaned about what a "loser" Scott is.
Stiles: Derek is your older brother which is highly awkward, considering how much Derek hates Stiles. Although you love Stiles very much, Derek always seems to be grumbling about how much he hates your boyfriend, which then makes you upset.
Jackson: Erica is your sister and even though you've always believed that she's the hotter one of the two of you, Jackson actually liked you better than her - which is surprising. Another surprising thing is that Erica and Jackson actually get on well...maybe it's a werewolf thing.
Derek: Isaac is your big brother so when Derek bit Isaac, you had to tag along with him considering your abusive father had died. Isaac seems to get along with Derek, which is a good thing considering you're dating the guy. The two of them only fight when they're working out together and preparing for full moons.
Isaac: You actually don't have any siblings, you're an only child. Isaac likes the fact you're an only child because it means he can have you all to himself and you don't have any family to worry about.
YOU ARE READING
Teen Wolf Preferences
FanfictionPreferences for Scott, Stiles, Derek, Jackson, Isaac and Liam; please ask if you want me to add another character. Enjoy!