That seems more like your interpretation of it; it’s merely an objective descriptor of the identity group in the same way that “straight white males” is.
I did not mean that the words "middle age mothers" are mysoginic or ageist in themselves. I was referring to the singling out of this particular identity group within the context of OP's message.
I should have quoted a longer part of that message for better clarity. I incorrectly assumed that my full comment was enough to contextualise what I meant.
