for the zillionth time, i'm sure that the OP meant the tone to be light-hearted, i'm certain that in her fantasy hilarious MN thread everyone would have been pissing themselves about how ghastly single women all love lettuce and hate children etc etc etc.
thing is, even when i was a nicely-dressed lettuce-eating single woman in a supermarket, i didn't sneer at mothers. i rather looked forward to being one, despite the pack of durex fetherlite in my basket. and now that i am a parent, i still don't encounter this sneering. and i've shopped in London, you know...
so given that the OP effectively insulted my former self by paranoidly instinuating that i would have sneered at her, just because her former self would have sneered at me, i think my first response was anodyne in the extreme and her first response passive-aggressively hostile in a way that much susrprised me tbh.
despite the fact that the rest of the thread wsa ho ho ho-ing away i just said that i didn't find it amusing and suggested another reason why those women could be looking, and suddenly it was a full-on discussion (albeit one characterised by yawnsome digs about oldies and newbies. interesting point by teuch earlier... what's better, 'oldies' ignore 'newbies', as is often the complaint, or answer them and then get abuse for it?)
fact is, childless is a loaded term. if the OP didn't know that before, she does now. and her OP wasn't funny. i bet there are fifty people who could have written the same thrust of an OP and couched it in genuinely amusing terms, which would have led to the discussion that some people wanted to have. but this was sneery and clunky and just generally naff about other women, about whose circumstances the OP was making huge assumptions.
but yes, let's make all this about an MN sense of humour failure... let's go off now and insult vast swathes of the female population just cos we don't look like them any more. let's start with women in pumps... they should be wearing high heels. and vice versa. join me, it'll be hilarious.
PS. your sister sounds like a right bizarre cow, riven. but you know her, you've spoken to her... seems reasonable to form an opinion about her.