They cannot.
The Constrictor Dhani respect Caiyha, but unless someone has at least three marks by her and preferably at least one from Siku, they are not welcome in Zinrah. And even those marked by Siku that are not Dhani will be shadowed and risk being eaten if they offend.
They will NOT at any point willingly take a living Myrian in there, because a) they're dangerous, b) their spirits will just run right back out and go and rat them out.
If by "nature raised Myrian" you mean a child that raised itself in the jungle, no. They do not exist.
Falyndar is brutal. Children die on their own. Even fully-trained adults can die. EVERYTHING wants to kill you and eat you. And I do mean everything.