My name is Jonathan Strange. Pleasure to meet you, Miss Diamond.

[ As Blue raises her hand to touch the gem, Strange looks awkward for a moment as he tries to find a way of looking at the gem that doesn't involve staring directly at her chest before realizing that really, it's a bit futile. And yep! That sure is a diamond in her chest. This really shows him how little he knows about...well, everything. ]

And by 'grow up,' I mean...change your form, I suppose. Age. Humans change their appearance as we go through our lifespan. A one month old human being looks different from an eight year old human being which looks different from an eighty year old human being.