Castlevania: Curse of Darkness question

[GrimReality]

Actually, Nan has the question, but she doesn't come here and has looked elsewhere to no avail.
She is wondering why her first fairy "innocent devil" is no longer getting evolve crystals, while the other IDs continue to do so.
The obvious retort is that it has evolved as far as it can go, right? Well, that is not the case as it shows how she can evolve further(hearsay, my friends, as I am not the one playing the game).
Can anyone offer any assistance here?
Thanks

[D-Rider]

It sounds like she might have switched it off, actually.  On the devil selection screen, you can toggle whether or not you want your chosen familiar to use the crystals you acquire.  This is so you can level it up without worrying about it changing into a form you don't want.