How Can I Argue My Case With My Parents?

First, are you the oldest? Do you have any other sisters? Trying to prove favoritism of your parents for your sister will be difficult. Ask for a family meeting. Ask your parents to listen to you and your brother for 5 minutes. Do NOT blame, find fault with your parents decisions. Speak one at a time. Talk about what is happening, describe how you feel, and illustrate accurately. I don't know what happened on Sunday, but I recommend something like this (I had younger brothers and a sister so I know) Mom and dad, last Sunday I felt angry when (sister) did (what you claim got you in trouble) because (whatever happened). Something like that. The key is to talk with your parents LISTENING TO EACH OTHER  and try to reach an agreement between all of you. I always seek a win-win resolution...a solution where everyone wins.

I find it somethmes not good to argue with parents. Makes things worse!

Hello young blood ;)  i seen your question here and i wanted to let you know my heart goes out to you ;) in a good way. i myself am the oldest of three sisters. And believe you me,  you can't present this as an argument to your parents. But tapeing you & your brothers opinion, and voicing your distress over little sisters immediate attention every time she isn't getting her way is an outstanding way to approach this. For your parents, this as well will give them an chance to hear your concerns in regards to sister, without them having to let her hear and becoming confused. If you are worried that they will not like the things you need to say, then you & brother can make a tape stating your views by using humor, and create a role playing point of view for them... Lol, that would be mixing a little humor with a little reality and i'm sure your parents would enjoy it as well...  And remember little sisters do grow up and can become one of your best friends if you can just hang in there. Lol..  I'm wishing you the best, and have fun with your  video tapeing ;)