Those Annoying Small Talks..

I read an article in FGB about some of the sexist things that one accidentally says at work. I am not sure whether what I am writing about here falls under that category and am looking for some guidance from the fellow team members here on how to cope up with them and respond to them without getting annoyed. Whenever I chance upon meeting an old acquaintance or a former team member or senior, non-executive board members and we are having this small talk before getting to the business at hand, I am invariably asked how old my children are, how I am managing to work full time in spite of their choc a bloc schedule w.r.t their studies and even have to hear one of those sinister (in the guise of well meaning) remarks on how they hope I have not left them in the lurch! Since I co-own a business, many of these contacts including a few family members just assume that I am here only during my free time to help out my spouse or keep an eye on him (for God's sake!). Somehow the fact that I am heading an independent business unit and am actively contributing to the company's revenue gets totally ignored. Most of the times I manage to keep myself composed in the face of such derision (intentional or otherwise) but sometimes they really get under my skin and I find myself fuming without knowing how to vent it out. It happened just a fortnight ago when an old friend I was chatting with, who was a mechanical engineer herself until a few years ago asked casually whether I was still assisting at work or had given it up. It is during moments like these that I get confused about what my response should be; whether I should - bare my teeth and bark at her or just carry on as though I did not hear those words.