My apologies that it has taken us a while to get to this: the audio in this phrase couldn't be fixed easily, and so it was slated to be re-recorded.
Looking at it again, however, I've realized that I actually misread the sentence the first time around, and somehow managed to make a typo in my response to you as well - my apologies for causing you confusion! I've fixed the typo my response now so that it will read properly to future users.
To respond to your original question: the sentence Nein, und Ihrer Angestellten auch nicht is grammatically correct, and it is referring to a single feminine employee. Ihrer Angestellten here is in the dative case (because of auffallen, as covered in the response above), and since it is feminine singular, we use Ihrer for the formal "your" and we also add an -n to Angestellte "employee."
The reason why we add the -n to Angestellte here isn't because it's a weak noun - as you've pointed out, most weak nouns are masculine. It's because this is an adjectival noun - that is, an adjective that is being used as a noun. Adjectival nouns obey the same rules as adjectives for their endings.
I hope that this clears everything up, and I do apologize for having misread the sentence initially! Let me know if you have any more questions on this.