Yes, it can happen, your siblings can fall to Twilight. If this happens, here's what to do:
If It's Your Sister Edit
This could be really difficult, especially if she's a hormonal teenage girl. If she hasn't got into it yet, direct her to anti-Twilight websites. Girls who have personalities similar to Bella's (ie. whiney, bitchey, immature) should be kept away at all costs, because they are the most likely to get caught up in Twilight.
- If they say it's the greatest book ever and Edward and Bella are in twu wuv, take one of the books from them and hit them upside the head with it. It may knock some sense into them....
- If they like it because their friends like it tell them that it is a passing fad. Just because their friends like it does not mean they have to.
- If she ignores you, wait it out. There is no cure for a rabid twihard. You have to wait it out until she gets over it. I feel your pain.
- If they are reading it for teh lulz then they're an anti, and nothing is wrong.
If It's Your Brother Edit
Don't lose hope. Your brother probably never had a girlfriend yet and thinks stalking and threatening a girl is the best way to be a good boyfriend. Burn his twilight books and give him feminist essays instead.