Feminism? - "The advocacy of women's rights on the basis of the equality of the sexes."

Or Femininity? - "Qualities or attributes regarded as characteristic of women."

Going strictly by the context of the translation it seems like they mean the latter.

I've never seen 女子力 translated as feminism and it really shouldn't be.
It's a weird concept...

I've always translated 女子力 as "girl power" myself.

I'd say it's closer in meaning to Girl Power, so it really should be Femininity rather than Feminism...