Juxtapositions. Jealousy is a normal human trait. Some are more jealous than others. It is a negative feeling. The only way to get rid of negative feeling is by positive feeling. Give her love and understanding and support and show her she's important to you. Even if she say's cutting remarks, remember that she is the one who has problem of negativity. If you go along and try to make more cutting remarks towards her then you too suffer from negativity. Understand that it is her problem and you will try to help her out of it by showing positive feelings. When you show positive feelings there is no reason for your cousins to think otherwise...