I love my 10 yo niece with all my heart but sometimes I don't like her very much.
I can't really explain it but it's like her personality is a little off. She comes across as very loud and almost arrogant when I know in reality she is actually a very insecure child.
I took her to the cinema at the weekend and during parts of the movie she shouted out unfunny "jokes" I asked her to stop as she was disturbing other patrons but she continued to do it a few times and afterwards I heard her telling her mother (who wasn't with us) how everybody in the cinema was laughing at her jokes 
If we are out for a family meal she will dominate conversation and ask to sing which her parents always shush the adults to allow her to sing (she has a decent singing voice but does anyone in a restaurant want to hear a 10 year old singing Ed sheeran songs!!)
She doesn't have many friends at all and a lot of my friends kids actively dislike her.
She is not my kid so I don't know how I'm supposed to help here? And can you even help if a kids personality is like this? Her parents think she is the best thing since Sliced bread