The two most REALLY important and valuable gifts you can give to any nurse or other medical or care worker (or come to that a teacher, or people employed in many other roles), are:
[snip]
2. A letter to their management saying the same thing, and that this person is a treasure to their organisation.
Especially this! My late father was an RN and one of his most treasured memories of his nursing days was when a patient wrote a letter to the hospital where he worked commending Dad for his thoroughness, kindness and professionalism.