She wasn't a feminist. Here's a letter copied and pasted from the Guardian a couple of days ago, sent in by a woman who ran refuge for women escaping domestic violence in 1979:
? Margaret Thatcher became prime minister in 1979 (Fiend or feminist?, G2, 6 January). I was running my refuge in Chiswick. What, as the first woman prime minister would she do for victims of domestic violence, I asked. I got a letter back to say that Margaret Thatcher was not interested in women's issues. A feminist icon? I think not.