Honey, I'm sorry to write this but you aren't going to be able to change Mom at this point. Your mom has been favoring your sister over you probably since forever and it hasn't anything to do with birthdays or whatever you might attribute it to. It has to do with your mom. She's set in her ways. You don't say if your sister contributes to this fiasco or if she sympathizes with you. Either way, you're going to have to move on with your life...you can't find a new mom or a new sister...you have to discover what is best about YOU! You're at an age now where you deserve to think about yourself and stop comparing yourself, or allowing yourself to be compared to an older sister. \n\nFirstborns can sometimes be the favorites for obvious reasons: They were there first. Perhaps your mom resented giving birth a second time so quickly after the first. Who knows? You don't need to know what makes your mom do this. You can ask her if you want but she probably will deny it is happening, or she'll put you down describing why your sister is better than you. ENOUGH! Haven't you punished yourself enough? \n\nBe polite, but firm when dealing with your mom from now on. You maybe will have to distance yourself from her for awhile. That doesn't mean you can't send Mother's Day gifts and birthday cards...but until you get yourself together and stop being her doormat, you need to find somewhere else to celebrate holidays. I would also consider counseling for this, as a counselor might have more and better ideas on how to deal with your mom's and your relationship. And how to improve your much-battered self-esteem.\n\nI really feel bad for you. It's really a shame that after all these years she can't understand how much she hurts you.\n\nTake care of yourself.