I don't know where you get the impression most activists are white middle class males, it is an international movement, and has supporters drawn from every nationality. Certainly many many women - I couldn't say if there are more women than men involved, but my guess, from my own experience , would be yes, it is more than 50% women.
Middle class? Maybe, as a lot of the older activists are retired professionals, doctors, lawyers, etc. But as I said earlier, we have a lot of youngsters too, who are too young to have a career yet
But a lot of protesters are graduates, and from graduate professions, so I guess that makes them middle class, even if they came from a working class back ground originally.
A lot are also ex military
The demographic treated most leniently by the police are definitely the over 80s; I have never known a single one held or charged, no matter what they do. Arrested, certainly, but almost always dearrested and driven home shortly after...whatever their sex, ethnic origin or income level!