The question above wants to analyze your writing skill. For that reason, I can't write your email, but I'll show you how to do it.
To write an email you must pay attention to the language that must be used. Formal language should be used whenever you are going to send this email to someone who is not intimate, or when the email has a professional, academic, or any other formal nature.
As the email you are about to write will be read by your cousin, you can write it in informal and relaxed language.
More information on how to write an email at the link:
https://brainly.com/question/25014341