If my ex-husband's wife is step-mother to my children, what relationship am I to my own children's half sister? This is not one of those strange riddles, this is a real quandary!!!!
no relationship is the simple answer! You are her step-dad's ex-wife/ her step-sibling's mother! I know what you are getting at - a very serious relationship your children now have is actually nothing to do with you - very strange! I am in a similar position although even more complicated!
Why not just opt for the handy catch all "Auntie"? It's far better then trying for anything more intimate, or even worse having kids call you by your first name which IMHO shows a lack of respect.
as long as you can maintain the authoritative adult / well behaved child relationship, i dont think the names matter too much. this particular one depends on if you ever have to care for you children's half sister, if you do then you're a step mum, if you dont then you're just part of the complex background that so many modern familes live with.
i'd have thought u were their step mum. i mean if she is ur childs step-mum, surely you would be her childs step mum? hmmm understand ya question though, very confusing x