The fact that you're even considering involving yourself in your daughter's work issues like that when she is old enough to DRINK is insane.

How did you establish yourself as a young graduate? By all means, give your daughter advice (if she’ll take it from you) but she has to navigate this situation herself or she’ll have no credibility with her colleagues

Let her work through it by herself. I worked predominantly with males in a hostile working environment (location rather than ppl) it may well be she’s clever but perhaps she’s not showing common sense ? They probably see her as a daughter or grandchild just like yours seeing her as a mum ? If you say anything you’ll make the situation worse probably, if the environment is as you say she had every opportunity to not work their through a choice, however she is so she will have to navigate it.