I think some people are reading a bit too much into this? I just dug out the quote and it seems she's just admiring another wizard's craftmanship:
'Complex' she replied 'Balanced, strong, sophisticated...it took real skill'
This to me simply reads 'Elaine sees new bracelet, recognises focus is quite complex, is probably impressed Harry (who is usually more of a brute force guy) made something quite so delicate.
By some people, you mean me. I am reading into it because I think it is a clue. You might read it and see nothing else. That's up to you. I am looking for more detail. On the surface you are correct. But as a buried clue... see where I am going? You have to read into things. Jim has done it consistently throughout the series. And don't think for a second that if it turns out the Elaine is Kumori that there won't have been hints. Or anyone else that we have met. There is a WOJ that we have enough information to work out her and Cowl's identity.
Arjan - But she makes no mention of the bracelet. Of course it is possible she didn't mention it. But it's a very glaring error in White Night. And Jim is both lazy and considered. He doesn't put some throw away small talk in a scene for no reason. It often comes back to bite.
And both of you forget that she isn't admiring the focus, what she specifically comments on is the quality of the shield itself, not the bracelet. She even says she isn't sure she could have made a focus for something that complex. Also, she doesn't see the bracelet in this scene. In fact, I am pretty sure she doesn't see it in any scene in White Night either. She only see's the shield. So your premise is wrong, Darkest-Before-Dawn.
Full quote:
She glanced up at me. "Like the new shield, by the way."
"Yeah. Sexy, huh?"
"Complex," she replied. "Balanced. Strong. Sophisticated. I'm not sure I could have made a focus for something like that. It took real skill, Harry."
I felt myself actually blush, absurdly pleased by the compliment. "Well, it isn't perfect. It takes a lot more juice than the old shield did.
Nothing about the actual design of the focus. Nothing about her even noticing it.
Even in Morris' example she doesn't actually see the new focus explicitly. Seeing an old focus and seeing an old shield are different things Morris. And as I stated above - she is commenting on the quality of the shield itself not the focus.