I worked on four different college campuses (student affairs) and here's what I think:
1. Contact the Director of the Women's Center in person (set an appointment with her receptionist), so you can talk about this face-to-face. During the summer, especially, it's really hard to reach faculty/staff because most of them are on vacation at one time or another. Don't assume she's blowing you off .... emails often take lower priority than an in-person appointment.
I would approach the meeting from a couple different perspectives:
A. Can we organize a bf support group on-campus, open to faculty/staff/students?
B. Is there a university-wide policy in re: bf and bf pump room availability?
C. What would need to be done to create a campus awareness and make this an issue that is addressed campus-wide, not just on an individual level (since you're concerned about other women who may not be as assertive about asking for help)?
(Bear in mind that unless you have a larger population of non-traditional students, this may not be a huge issue on her radar - numbers matter and if only a few women on campus are even in a condition to be considering bf, then it's likely to be a lower priority for her than the more "traditional" women's issues, like sexual assault, body image issues, sexual harassment, etc. -- So you may end up having to "sell" bf support to her a little bit as a priority)
2. If you know your degree, work within your department. Approach a prof whom you like/respect, and see what they might know about in terms of availability within the department. Perhaps there's an unused office, or perhaps the prof would loan his/her office during the time you need to pump, or etc. I think you're most likely to find accomodations on an individual and immediate level, via this route. It's actually probably not so big an issue for your female profs, because they have their own offices and just close and lock the door when it's pumping time, if they're bf.
But there may already be some system in place for other students who are bf, that you can transition right into.
3. I agree that you should be able to find empty classrooms etc., the key is to have availability that works for *you.* It's unlikely that the school is going to be able to modify each building to provide pumping space (at least, in the timeframes universities work within, not within the next couple years) -- but each building WILL likely have a room available at the time you need to pump, which doesn't include the bathrooms. The office to contact about this, would be the Facilities office (or whatever they call the office which is in charge of cleaning and maintenance in all the buildings). Additionally, if you check with the Advising office you are likely to find someone who can access the room systems to let you know (as well) when rooms are empty. I know the last college I worked at, would have been able to "reserve" a room for you at X time daily for the entire semester, so that if a prof wanted to have a study group there or etc., or the cleaning crew wanted to clean, they'd know it was occupied and schedule accordingly. Many, many universities have such computerized systems now (I'd also double-check with the Dept'l Sec'ys in the buildings in question to make sure they're aware too, because of the tendency towards independence which also happens on university campuses
Other rooms to consider, if you've got longer breaks and want a nicer surrounding than an empty classroom or storage room ... many campuses now have "study rooms" which students can check out keys for (or even conference rooms) in their residence halls.
You can reserve those rooms for free as a university student (often even if you don't live in the halls) and have a semester-long reservation for those, too. Also, there's the student union (which also often will have a nice empty room somewhere and may not charge you - although they're more likely to charge, so that might be a place where the Women's Center could assist in getting that not to happen).
And the Health Center is always a good option and you'd probably find something there that can help you.
If you encounter hostility or stonewalling
- the Dean of Students' office, or else the Ombudsman, or both, would be able to mediate and work with you on the issue as well. Fewer schools have ombudsmen than a Dean of Students, so look there first.
IMO (and recall that I was a staff?faculty member, but I worked with students directly) -- universities in the end are bureaucratic and slow to act, and frankly the perspective from the university itself is that students are only there for 4-5 years, and therefore they are more likely to move on issues that are also impacting staff/faculty (and faculty/staff get better parking etc.) .... Students are the money source, but they're also transitional and move on before they're savvy enough to manipulate for widespread change, KWIM? So the status quo is hard to change from a student perspective. Once students have been in the system long enough that they know what needs changing, they're near graduation and either apathetic, or else struggling to convince the frosh/sophs that it's a big enough issue to become involved with it ....