True, though I was under the impression that the children (at least the ones focused on in this game, not the wesker series) were cloned from her? If I'm getting it mixed up, that's my bad, but I could have sworn that was either mentioned or at least heavily hinted at, but I didn't consider what the connection with Emily specifically could imply. If my original impression stands, then the potential for further mutation could certainly be there based solely on the mutations shown in the children, as that would mean it's latent to the DNA.(unless they just messed up the cloning process, of course.)
Actually, now that I'm thinking, I think there might have been two sets of clone children instead of continued iterations of one series, like I can only assume that they did with their Weskers. Let's say she's a clone herself, and just happened to be the most normal one out of the batch. The children shown in the flashback sequence are certainly clones, and she's roughly the same age at the time give or take a few years. The reason Emily looks more normal could be because they started working with samples directly obtained from the most normal clone.
Sorry if this is incoherent at all, or common knowledge which I'm pretty sure it actually is, I quite literally just rolled out of bed, haha.