Ortiz- cofer (the author of the story "first love") chooses to include her thoughts and conclusions as an adult at the end of her memoir about the "sweet anguish" of her first love experience that she had at the age of 14. how does this change the memoir as a whole? how would the story be different if she left those final thoughts

Including thoughts and conclusions as an adult makes the memories more meaningful, because she can prove how those memories affected her adult thinking, and how it was important to form who she is today and how her thinking has evolved over the years. That is, by including adult thoughts, the author shows how these thoughts were influenced by what happened to her at 14 and that makes the memory more meaningful and important.

If she did not include these thoughts, we would think that that memory was only important to her at that time, but that it did not teach her anything, nor did it influence her adult life, that is, it would seem that the memory did not have much significance.

about the letter or who wrote the letter

the answer is both an appeal to ethos and logos (if that's what your question options were)