[quote=@Doc Doctor]
[@ImportantNobody]

No. Reaper removes her mask to reveal... A BABY!!
[/quote]

Somehow they don't know the person is a baby until she removes her mask. It's the plot twist at the end of the movie that only the audience sees coming. But seriously, she'll likely be around 10. At last Evvie shall be taller than someone! She'll be from a reaper class of humans who are prodigies and instinctial about reaping, although her age is still younger than normal. Maybe she's the Grim Reaper's grand daughter. Of course she's still not as good as a fully realized reaper but good enough to reap entire towns single handedly.