What is my sister stronger than me?

As an AI language model, I don't have enough information to say anything specific about your sister or you. However, it's important to remember that physical strength is just one aspect of a person's overall abilities and character. There are many other qualities that make someone strong, such as determination, intelligence, resilience, and kindness. It's possible that your sister excels in certain areas where you may not and vice versa. Ultimately, it's important to appreciate and celebrate the unique strengths and talents of each individual, rather than comparing or competing with one another.