「(Situation or event) + （だ）から + と言ってなんだ（、） + というわけ + では/でも/じゃ + ない」
In short, this is a set phrase to make things vague. It being a set phrase is the important point because it will enable the listener or reader to know automatically that the speaker or writer is being purposely vague about something.
Because it is a phrase to make things vague, it can be difficult to translate it naturally into a language (or culture) where vagueness is not regarded as virtue --- or at least not as much as it is in the Japanese culture.
Notice the two quotative 「と's」. That would already be a good sign of "vagueness", wouldn't it? No one actually has said or heard anything regarding the fact that the girl was there. Nor the speaker is about to make a meaningful comment on that fact.
The speaker basically has nothing concrete to say here, which is why 「なんだ」 is being used instead of a meaningful phrase or even one "real" adjective. He is at a loss of words.
If you absolutely need a translation, you could use:
"It is not that I want to make a (particular) statement (about the situation)."
"It is not that a discussion is in order (about the situation)."
"(She was there.) Not that it is important."
Point is, no matter how you translate it, you will not be able to translate it back to the original Japanese phrase in question. That is the limitation of a translation method in foreign language studies.