Well, the lowest ranked female soldiers we've seen so far have been Elite Soldatos (a.k.a., "the Elites"), who are Lelianna (in 2 of Wilfred's contracts, and one of Isabel's freeroam events), and Alexa (only in one of Wilfred's contracts, though can see how she looks through special renders), but Elites can wear what they want.
But you're right. All these Serpents (Cynthia), Capos (Caterina, Amita, Amata), Wilfred's Division (Onorina, Elita, and others) I guess would have been at one point started off from soldatos position. Yet it's especially apparent there haven't appeared any in terms of MC's generation i.e. Luna, Gracie, Eiza (Luna's a Capo, and Eiza's at least an Elite from what she is claiming to be).
As for other Families, well Hopes talked about this before;
Previously, several years ago the crime world of DeLuca was very male-centric/dominating society (where belief was women shouldn't have power and were discriminated).
However, Cordia coming into the picture changed things. Cordia, with her rise to power after the Big War elevated DeLucas status in the heirarchy, basically changing the power dynamics of the Big 5 Crime Families (some of the families were ousted from Big 5, and some new families including DeLucas took their place as part of of Big 5).
With that came the reform where Cordia tried to changed the system from the old ways (where women are more accepted in positions of power).
Some families grew to accept female soldiers into the Family (whereas some did not).
So with other Families, it's gonna be dependent on whether they are Pro-Cordia's reform or..... not (Old ways loyalists).
So far in season 1, not much has been explicitly told about a Family's stance.
Though I guess one can make educated guesses:
- Fazio Family: most likely Pro-Cordia's reform. While no female soldiers are shown of the Family (yet), their Don Giocabbe is one of Cordia's friends and allies and supported her in the Big War.
- Ombra Family: initially leaning heavily leaning towards Old Ways loyalist (given how Nazazi behaves normally, and Quinzio's comments regarding "How unhappy he is with how things are now"), though extent of it's slightly lessoned Nazazi softening up to his daughters and going through depression (when he put his wife in charge for a period)
- Kaskar Family: A bit iffy on this one. Seems like they are neither allies nor enemies to DeLucas in terms of families' relationship. And no female soldiers are shown.
Though I guess that one slipper scene with Aunt Layla
might have me guessing that the Family might be slightly leaning towards Pro-Cordia reform (despite it being a scene for laughs).
Heh, initially thought of doing a quick reply, but it became a long rant
HopesGaming, feel free to correct me for anything incorrect.