If you are on twitter you are only in touch with a very limited number of organisations, as it is one of the least used SM outlets. But does of course have all the duelling individualists if that is off interest.
The best source of information is still old fashioned newsletters, but like different SM outlets, there is no one newsletter that has everything.
And cumbersome as it is, if you are interested in more than opinions Facebook has a far wider range of women's groups, mainly because it has trillions more users than twitter, so not surprising.
But if you can set up a newsfeed this can throw up information that you dont get on SM, because belief it or not, most women's groups activism takes place in local areas and so they have info in local papers etc.. which news feeds pick up on.
Just as the other day, randomly from an Irish papers I saw that there was to be a consultation about the Women's Pond in Hampstead.
Although later it did appear as news from most other papers.