The real problem here is the use of the term "feminist". When a person chooses to label himself as "part of X", it is natural that others will associate his actions with other people who have done the same, regardless of whether he actually agrees with them. I choose not to "identify as an atheist", because it would associate me with those who take the stance that religious people should be shot. There is nothing to be gained from self-applying the label and quite a bit to lose. Some labels cannot be avoided so easily. I can't just stop being "that tranny", for example, because it's not a label i choose for myself, and members of Islam cannot just stop calling themselves Islamic as it is a necessary part of their belief system. "Feminist", however, is almost entirely a self-applied term (though there are some feminists out there who actively force it on others.
/me points at "find a feminist in popular culture and explain your reasoning" 'women's studies' homework assignments :P). There is nothing to be gained (and quite a bit to lose) from labeling your charity as a "feminist charity". Rather than choosing whether or not to donate based on the merits of the cause, some people will read the name and immediately discount any work being done. Let your actions speak for you rather than some meaningless label.