Does な originating from ~にある mean you can replace な with ~にある today?


It has been said [elsewhere](https://japanese.stackexchange.com/a/19184/51280)
that だ, な, and の all originate in some for another from Old Japanese copulas.
E.g.:

  * だ originates from ~である
  * の sometimes marks the genitive/possessive case, but sometimes it is just the copula (in which case it can be replaced by ~である)
  * **な originates from ~にある**

**Main Question:** Does this mean everyone one sees the attributive copula な,
one could _in principle_ replace it with ~にある? (I'm likewise curious about
replacing だ with である, but should probably keep this post focused).

**Attempted Counter-Example:**

> 彼女は **綺麗な** 女性です
>
> **Literally:** As for her, she's an is-beautiful (綺麗な) woman.
>
> **Idiomatically:** She's a beautiful woman.

> 彼女は **綺麗にある** 女性です
>
> **Literally:** As for her, she's located inside beauty. (???)
>
> **Idiomatically:** ???

This doesn't seem to make any sense? Perhaps the attributive copula な does
originate from ~にある, but ~にある was used completely differently than it is today
in modern Japanese?

