Only a short period of time has passed since the Horde and Alliance joined forces with the night elves to repel the attack upon Nordrassil. As such, night elves and humans have not found sufficient time to mingle and produce adult offspring, and that any crossbreeds with humans are currently children or babies.
In addition, it is unclear that the two races would actually couple due to prejudice or disdain, even if both humans and night elves are Alliance members.  But as humans are confirmed to be able to interbreed with high elves, which came from the night elves (see half-elf), night elves should be able to interbreed with humans as well.
Specific individuals Edit
- There is no direct evidence any half-night elves exist in-game or in lore.
- Lelior and his mother - Half-night elf half-troll. His mother is said to be a half-troll. The only reference is a "your mother joke" which isn't accurate at all.
- Thel'danis, is a bugged NPC.
Due to the confirmed existence of half-elves (Half quel'dorei and human) it may be speculated that if both humans (for humans are the most common race to breed with high elves so it stands to reason the same would hold true for night elves) However, Kaldorei are as akin to Sin'dorei as a panther is to a common housecat.