I'm confused by CW's 90210 can someone explain it to me?

I understand the storyline with Jessica Stroup's character, Tristan Wilds, his characters sister on the show and the parents. The blonde girl I think is just having trouble with her boyfriend and her dad's new woman. What's with the blonde teacher who's silvers sister which is weird because she's way older than silver. Whats with her husband or boyfriend trouble's? Who's her daughter, husband, boyfriend?