It's just so over the top! Feminism is good, but that's just stupid! It made me laugh so hard. :-D I would never had thought, that anyone actually uses it.
Sounds too much like Bertha for me. I don't like the name Bertha. If you want to honor the Earth, consider going with Gaia or Terra. They're prettier and less obvious.
I'm totally in love with this name. It always reminds me of Eartha Kitt, whom I don't know much about, but luckily I haven't heard anything negative about her.