Is it normal to be jealous of someone ?

My niece is 10 years younger than me. She's the most popular girl in our town. She knows everyone and everyone knows her. She has over 1,000 friends on Facebook even some celebrities added her. Whenever I try to add some of her friends they either sent me a message and ask if they know me or ask who I am or they ignore my request and block me. She was one of the popular girls at both of her schools. Her home school and one she went to where kids from different counties come to try out and see what it's like for a job. She's friends with everyone from both of them. I got a rude message from one of her friends it said " why the hell are you trying to add me ? ! ". Then another girl messaged me and asked " who are you ? " and I accidentally hit the like button and liked the message and she wrote back " that does not answer my question " then she unfriend me. She and her husband and kids live in town me and my husband live way out in the country where we have a few houses around us we never go into town. Not even my own cousin would add me she's friends with her and she's my favorite cousin and not even her other uncle would add me. She's friends with both of them. I tried to sent them requests they ignored it and blocked me. I'm so mad and jealous even though she's my favorite niece I love her to death I'm jealous she's so popular and I'm not not even some of my own family would add me. Is it normal to be jealous of her ? How did she get so popular ?