My cousin cannot enter to us at jfk last night. She has epassport and esta. Do you know someone who could help her to find out why?

ETSA does not guarantee admission. An attorney may be able to explain what happened. Your cousin would need to produce copies of all correspondence received from CBP as well as any notation provided in her passport. Once an attorney reviews this information, he/she may be able to provide more insight into why your cousin was denied entry.