Ok so yeah, I was beginning to suspect once she mentioned having no memories and therefore doesn’t remember her human name, but then it just went and confirmed that yeah, nah, that straight up is just Merize. My main point against that being the case was that Merize just doesn’t sound like a human name, but if she can’t remember her real one, something like this could easily happen.
One other idea I had thought that could still dodge the whole potential relatives situation is that Iruma is a reincarnation of Merize. Ameri is older than Iruma, but I’m pretty sure it’s at least implied she doesn’t remember her mum very well if I’m remembering right, so there’s definitely room for her to have died either before or at the exact moment Iruma was born. Dunno if it makes it better that instead of being genetically related, Ameri just has the hots for her mums reincarnated soul, but yeah, I dunno, I’m sure it’ll all work out. Hell, maybe Sullivan just saw Iruma, realised he looked a lot like Merize and thought “Hey, I bet Henri’ll have a way harder time trying to deport someone who looks just like his wife!” and that’s literally it. Guess we’ll just have to wait and see.