Sinn Fein will find it difficult indeed to exist without its Catholic identity, but that is true of other organizations which have done so as well, even to the point of silencing its pro-life members.
It may also be supposed that now Sinn Fein is revealing itself from its Revolutionary and Socialist, even Communist influences revealing what it was all along, a Revolutionary organization.
Reports have been coming from Ireland that Sinn Fein is silencing its pro-life membership. Of course, like Ted Kennedy, they are also serious dissenters on the Catholic teaching against abortion. We found some substantiation for this in the following report, here at the Devin McAlisky blog entitled, "Is Sinn Fein Sort of Revolutionary?" (They've always been that)
Probably the best evidence that some very large majority of SF members are feminist is their position(s) on abortion (bear in mind, there would be a lot of SF members who are pro-life but nonetheless feminist).
1) In 1985, although it was apparently a very unrepresentative vote, SF did, for one year, adopt a pro-choice position.
2) Although Sinn Fein MLAs did vote for a Democratic Unionist Party motion, which opposed the extension of the Abortion Act to N. Ireland (abortion is almost completely illegal there). It’s not that simple. A member of the Women's Coalition proposed an amendment that radically changed the resolution so that it simply referred the issue to the Health-Care Committee for further research, discussion, and debate. SF members spoke (starts half-way through, you'll want to look at this to see who's who) and voted in favor of this, and when they spoke, they made it clear their party is not fully committed to the pro-life position.
3) In 2004 (possibly 2003, but I'm pretty sure 2004) SF Youth came within one vote of adopting a pro-choice position.
4) SF's current abortion position is that they support abortion when the life or health of the mother (I think that might also apply to the fetus as well) is at risk, in cases of rape or incest (in the 2002 Abortion referendum in the South, SF also were okay with abortion when the woman is suicidal). They also feel very strongly about not criminalizing women who have abortions.