相手には when speaking of "two third persons"


I want to clarify my understanding of 相手には in the following sentence...

「人見知りをしない **相手には** 強気なところがあるよな」

It refers to a person that usually acts rather shy around others but scolded
one of her acquaintances for his previous behavior. The preceding clause:
「旦那に対して説教をしていた」sounds to me as if it is the 旦那 is being scolded.

What confuses me is 「人見知りをしない相手には」so far I understood 相手 as a person (etc.)
different than the doer of an action. In combination with 人見知りをしない I thought
of it as "A person the aforementioned shy-person is actually familiar with and
therefore not acting bashful".

To cut to the chase I am struggling with the meaning of 相手には in context
between two third persons (from the narrator's view).




This 人見知りをしない相手 is "someone who she won't be reserved/shy with". That is, 相手
refers to the person she talks with, but the subject of 人見知りをする is the female
person herself. This is an example of [adverbial-head relative
clauses](https://japanese.stackexchange.com/a/54677/5010). Please read [this
discussion](https://japanese.stackexchange.com/a/64630/5010), too.

> 彼女は彼に人見知りをしない。  
>  She is not shy with him.
>
> ↓
>
> (彼女が)人見知りをしない人  
>  someone who she is not shy with

In other words, the sentence is saying she is an
[内弁慶](https://jisho.org/search/%E5%86%85%E5%BC%81%E6%85%B6).




This 人見知りをしない相手 is "someone who she won't be reserved/shy with". That is, 相手
refers to the person she talks with, but the subject of 人見知りをする is the female
person herself. This is an example of [adverbial-head relative
clauses](https://japanese.stackexchange.com/a/54677/5010). Please read [this
discussion](https://japanese.stackexchange.com/a/64630/5010), too.

> 彼女は彼に人見知りをしない。  
>  She is not shy with him.
>
> ↓
>
> (彼女が)人見知りをしない人  
>  someone who she is not shy with

In other words, the sentence is saying she is an
[内弁慶](https://jisho.org/search/%E5%86%85%E5%BC%81%E6%85%B6).

