DD reported "I didn't know how to describe respect. I could only think of what wasn't respectful."
My son in 1st grade was asked to do a similar writing assignment on "Trust". He ended up writing whatever thoughts came to his mind. He wrote about what wasn't trustworthy in his opinion because that is all he could come up with at that age under such short notice. The teacher actually liked his writeup which is why I got to know about it (she pinned it to the bulletin board of the class during back to school week).
If your daughter can only think of what isn't respectful, at age 5, I would absolutely encourage her to put her thoughts into paper - it is still "on topic" as far as I am concerned. The teacher can then work with her about how to modify it or not.
PS: I agree that this topic is very nebulous for a 5 year old and 6 sentences is too much of a writing work load.
