I personally have no problems whatsoever with the word 'mama' as that is how we say 'mum' in Polish, and in many other languages actually. I bet your kids actually said 'mama' for the first time, rather than 'mum' or 'mummy', so I don't understand why that should annoy anyone. Of course, I'm all for a light-hearted laugh, but I did also notice the sort of made-up group naming (yummy mummy, etc.), as Convex noticed earlier, which is just bull**** in my humble opinion (oh, how I was tempted to write IMHO!), hehehe. Now, being referred to as 'Mummy' by a health visitor is just lack of professionalism and smacks of over-protectiveness.