Noel is much younger than all the other dark ones, though. she was born when the Pact was made because Nael was too powerful.
it's possible Noel was the only virgin among the dark ones
Nael could potentially also be one, up until she met Gab, as there was no one powerful enough to fuck her xD most being won't even look her in the eye...
reason is simple enough, it would be a risk to have it at home and on the way home, as it could be stolen, or even just touched by anyone like her daughter and potentially expose the world of companions and dark ones if it happens at the wrong time and place. keeping the secret is very high in their priorities.