She had it since before the Grom curse, and is studying the collectors (I read it as was also doing that before the curse?), and of course she also had the Grom curse on her in the first place.

None of that has been expanded on yet, but I think Enna’s gonna play a pretty big role here soon. My money’s on this coming up in the next serialized story, also featuring the war with the Titan Trapeprs