Maybe Nia would be interested with talking to Ellen, there is elf in her. She has the same eyes as Maria and we saw how pissed Nia was when they messed with the half-elf. Ellen would make an intelligent choice as the Nia's informant, Ellen is the brains behind the Hotel's operation and comes across as the matriarch. She would also have reason to fear the system might come for her one day so she has an interest in bringing it down.
Ellen has shown that when the chips are down and nobody knows what to do, she steps up and fixes it. Ellen kept quiet and worked behind the scenes to bring our girl back home.