Question about the phrase「挑みかかる手前な顔」


I cannot understand the meaning of 手前 in the following sentence. As far as I
know 手前 means "in front of my/your hands" or could be a pronoun. However I
haven't seen before the usage like in the sentence below, so could you please
explain the meaning.

> 着物姿の女の子なんて珍しいから、つい眼で追いかけてしまっていた。眼が合って、彼女は口を引き結んで、僕の前で挑みかかる **手前な** 顔をして。

Translation attempt:

> "Because it is pretty rare to see a girl wearing kimono, my eyes
> unintentionally followed her. Our eyes met, she tighten one's jaw and right
> in front of me..."

~Edited: I think I'm more or less understand the meaning, thanks to Brandon.
But I also can't figure out why it's used な here, as if 手前 is na-adjective?




手前【てまえ】 has a number of uses; the pronoun being the much rarer case. Here it
means "before" as in time.

挑みかかる手前な顔 A face one would make just before initiating a challenge.

> My eyes locked onto her; what with a girl dressed in a kimono being far from
> common. Our eyes met and she pursed her lips and made a face as if to say
> "bring it on".




手前【てまえ】 has a number of uses; the pronoun being the much rarer case. Here it
means "before" as in time.

挑みかかる手前な顔 A face one would make just before initiating a challenge.

> My eyes locked onto her; what with a girl dressed in a kimono being far from
> common. Our eyes met and she pursed her lips and made a face as if to say
> "bring it on".

