Family advice please help?

Okay well I met my cousin when I was four years old. I only met her once in my life. She lives about 7 hours away from us. When my aunt (her mother) died we did not go to her wake because her body would not be there. Her daughter had her cremated. I had not seen my aunt since I was four years old. But I did talk to her over the phone and so did my parents. My cousin never kept in contact much only sometimes over the phone. She never returned calls or told her daughter to say thank you for a birthday gift we sent her. She sent me a message over facebook asking how everything was ect. Last Christmas I sent her a message on facebook wishing her and her family a Merry Christmas and she never responded. Well my cousin has three children now. I have never met them but I wish to. I do not understand why. My mother said that I am the furthest thing from her mind. I agree with her. Other family members besides her had children and I want to meet my other cousins too. For some reason I feel that someday I won't have family because I'm the only child. Why do I get upset that I can't meet them?