Competitiveness with your older sister, in addition to thwarting a positive relationship between the two of you, may have negative ramifications to your psyche. Sibling rivalry involving issues of equality and fairness seems to correlate with a substantially increased risk of depression, according to the 2010 study "'Who Said You Could Wear My Sweater?' Adolescent Siblings’ Conflicts and Associations With Relationship Quality," by Nicole Campione-Barr and Judith G. Smetana. Take steps to break out of the rivalrous routine and celebrate your accomplishments as an individual.

Improving Self-Esteem

A less than favorable estimation of yourself could be at the heart of your perception that your big sister does everything better than you. The hallmark thoughts and feelings of low self-esteem can lead you to exaggerate others' accomplishments while minimizing your own. You can boost your self-esteem with some cognitive reframing exercises in which you replace negative thoughts with constructive ones, according to psychologist Jeffrey Bernstein in the 2013 article "Four Helpful Thoughts for Kids and Teens to Build Self-Esteem." When you start to mentally lambaste yourself for not being as good as your sister, question the accuracy of that thought and then replace it with reminders of your own past successes.

Find Your Passion

It's highly unlikely that your sister bests you at everything. You may have this perception because you have only pursued the same talents and activities in which she has already gained experience. Let the sky be your limit as you dream up potential undertakings. You could try out for the school soccer team, audition for a community play, or fill canvasses with scenes from your imagination. If you're concerned based on past competition that your sister may hone in on your territory, keep your interests to yourself, at least until you feel more firmly established in them.

Ask for Validation

While it is ultimately important to rely on your own sense of self-worth and accomplishment, it is perfectly natural to crave validation within your family. Consider that your parents and other close relatives may not even be aware that you're constantly feeling outshone by your older sister. Try having a discussion in which you allow yourself to be vulnerable. Express that you feel discouraged because it seems that your sister garners all the attention in pursuits that also matter to you. While you can't expect them to ask your sister to give up her interests or to stop displaying their pride in her, you can expect them to confirm your talents as well.

Teammates, Not Rivals

From Tommie and Hank Aaron in baseball to Donny and Marie Osmond in music, many siblings have famously come together to accomplish great things. If you're both interested in a certain hobby, try approaching it as teammates. Even when a pursuit involves competition by nature, such as basketball practice, you can approach it with a cooperative mindset. Talk to big sis about using the competition to help each of you be your personal best. If you both love to paint, compliment her landscape and ask her to advise you on the most realistic way to shade mountains. Hopefully, your attitude will rub off on her and she will acknowledge your areas of strength.