While I may not advocate her position in regards to gaming and sexism, I believe she has every right to ask for donations for any cause she sees fit, be it in USD or Bitcoins. Donations are voluntary, you don't have to donate if you do not support her position.

@OP Why don't you ask them directly if they would accept donations in Bitcoins? They have a contact form on their website.
http://www.feministfrequency.com/contact/

In my opinion, the more people accept Bitcoin for any purpose, the merrier.