Right now, you are starting to feel the effects of learning from the world around you as opposed to the school-like way of learning from books. Here's a tip to make it easier, read the stuff you are interested in and then apply it to what you are doing in school! I know, fractions are really hard but think about how it applies to the number of M&M's in a bag or how full your bowl of ice cream is. Trust me. You will be so happy with this later.
I know you desperately want the nuns and teachers to like you as much as they like L. It seems like because she learns differently than you, they like her better. She's not better than you, just different. You need to learn how to be friends with your sister because later in life you will regret fighting with her for so many years and will wonder what it would have been like to have that close friendship you missed out on. I know she is mean but just try.
Treasure the time you have with Mom and Dad. They love you like no one else and will do everything within their power to make you happy. Spend time with them. Find out about their childhoods and what it was like for them growing up. Do the same for Ada next door and any of Mom's elderly friends. These people have so much wonderful things to share with you.
You are beautiful, always. Don't try to do things to get people to like you. This is important now and as you get older. I can't go into specifics now but turning yourself inside out to make yourself something you are not will hurt later.
I really don't know how to end this letter. Just know I love you little person and I hope to love the person you will become.