I took a class on the civil war a while back, and the strong female presence was mentioned (among others the Mujeres libres) - as soldiers but also in many other roles. At the same time I remember that despite this, women were often not accepted in these new gender roles and that there continued hierarchies eg between male and female soldiers. But also continuing hierarchies within the different left groups (from a current view) in spite of their revolutionary ideals.
I could also imagine that women could have held quite different positions say in revolutionary Catalonia than in other regions. Lastly I was wondering if claims of this participation being exceptional at the time hold up. Would be glad for info on any of these questions.
I answered a question touching on both Mujeres Libres and the milicianas a couple of months back, but it sounds like it is covering very similar ground to your class discussion and there is certainly plenty of room for further contributions. Happy to try and address follow ups, but my direct (ie research-led) knowledge here is not extensive, though it's a fascinating topic!
With regards to the specific additional questions you mentioned, I wouldn't necessarily expect vastly different outcomes in Catalonia compared to elsewhere in Spain, as anarchists were just as (or more) prone to seeing politics and war as inherently masculine spheres that excluded substantive female participation. There may be some exceptions - greater progress in collectivising agriculture and industry, for instance, might mean more progress in terms of collectivising childcare for women workers, but I don't know of any specific research looking at how this might have differed across regions. As for exceptionality, this is tricky. The participation of women as fighters was certainly distinctive - as the equally enthralled/horrified international media response makes clear - but was hardly completely unique (women's involvement in the Russian Revolution springs to mind), especially considering the more limited reality of women's involvement at the front. Women's participation in the broader revolution was, I think, less distinctive. Women had been in involved in revolutionary/anti-fascist movements throughout the interwar period across many contexts, though they often also had to struggle against entrenched gender norms that limited the perceived scope of women's political involvement. Broadly speaking though, those activists that went to Spain tended to be disappointed rather than inspired by the extent of women's participation in the Spanish revolution.