[USFSDTAlum]

My dad was married before he married my mom and they had kids(me and my brother). His first wife...is she my step-mom? my ex step-mom? Simply "My dad's first wife?" I know that my sister from that marriage is my half-sister, but are there any terms excompassing her(my dad's first wife) children that came later, now that the marriage is over.

I feel like when I talk about these people I confuse the living daylights out of people, 'My half-sisters, half-brother, who I am not related to, is getting married. Blah blah blah. There's got to be a quicker way to refer to these people, not by name.