You know, if the females are taller/bigger, and Castiel is female, does that mean Gabriel being shorter is a male? Is his obnoxious chatter the angel version of male songbird calls ('this is my place!' 'I've got a good food source/nesting ground!' 'Mate with me and your eggs will have a high chance of survival!') because if so... I can see angels being utterly confused by humanity.

Does Cas think Dean and Sam (especially Sam!) are also female at first?!