How do you feel about using accents or a diaeresis above vowels?

For an American kid, how do you feel about using an accent above a letter like é, or a diaeresis like ë? For example my middle name is Reneé so it's pronounced Re-nay (like Renea) instead of Re-nee, or with a diaeresis you could do Zoë or Noëlla. My understanding of a diaeresis is just that it tells you that that letter is to be pronounced with its own syllable, so a more defined Zoh-ee instead of just Zoee or Noh-eh-lla instead of Noh-ella. I know they're really common in other languages and countries but you hardly see them in America unless the child or his parents are foreign or something.