As the younger sister, you always feel your sister’s support and see her as someone you can always trust. Although sometimes you discussed and don’t agree on everything, you trust her completely. Having a sister is having a best friend for life; the bound is so special that you feel that no one can ever break it. Your older sister is the only person who knows you completely and still accepts and loves you.
This is why having an older sister is the most precious thing you can have in your life.