I would prefer it if we stick to the more lingering tennets of the lore, and as such any attempts at female astartes would be... less than ideal. As long as you are okay with putting up with, likely, distrust from fellows then I do suppose it could be worked in somewhere.

Besides. In the meat grinders of war, the side with more soldiers tends to win. You will however, have to make a specialised chapter for this. As I would like to stay mostly in tune with the founding chapters and their successors being more true to lore.