To be honest, most of the judgment about not being a Mom happens outside work. My husband's mother and brother make comments every opportunity they get. Just one of MANY examples: my BIL to his 12yo stepson (in front of me) when I invited them for lunch "... and... live in a 3 bed house but there's only 2 of them".
My MIL makes constant remarks, e.g while watching tv "Did you freeze your eggs?". Lots of comments like this all the time. We made it clear that our business is private and between us. Two weeks later: "I have an article of IVF I tore out of a magazine on the hairdressers for ye".
Both my MIL and BIL call me a "career woman" in a disparaging way.
On my side, my brother's wife has made a number of comments usually only woth drink on board. One example: "It's not a man's world. It's a man's and women without kid's world. The only women with senior roles in my office don't have kids". My response: "I've had to work really hard to get to where I am, are you saying I only got here because I don't have kids and not from my hard work and persistence?". Her: "Yes, that's exactly what I'm saying". So apparently any achievement I have is not really an achievement.
My sister said about an elderly family friend "The tragedy of her life is that she never had kids". To me. Maybe not directly relating to my circumstance, but still.
A number of my school friends have made pointed comments too, e.g. about my DH (who by the way didn't want kids and is relieved we weren't able to have any in the end): "It's such a shame you don't have children as would make such an amazing Dad". That was one of the most hurtful comments. Cut like a knife. She's my friend. Why wouldn't she say I'd make an amazing Mum at least. I felt she made underlying assumptions and blame. Also, not sure why she said it in first place as we weren't talking about kids.
The friends who are on my side still say things like "X (me) is so good with children" in a surprised tone or to explain to others that leaving me alone with their kids won't end in disaster. That feels pretty hurtful too: the assumption that because I don't have kids I wouldn't be good with them.
In a work context I do get less judgment for not being a Mom. The judgment I receive there is more related to criticising my leadership skills in a way they likely wouldn't if I were male. Though people do feel uncomfortable when they ask "Do you have kids?", which is a completely fair question and I have no problem with. The problem I have is their reaction to my answer ... from shocked silence to staring at the ground awkwardly, I've had it all. I found the answers "No, just my husband and I"; "No, I'm a family of two"; and "No" evoked silence and shock so now I say "No, but I'm very close to my niece and nephews" and I find that gives people something to grip onto ... it enables them to ask the usual follow on questions "what age, etc". A few years ago I always got "Oh, not yet" but now I am mid forties, I don't get that any more. Weird though that after "No, just my husband and I", nobody ever thinks to ask "Oh what does your husband do?". It's like they have this one follow up question about kids ready and if they can't use that, they don't know what to say.
At the Xmas party in December one colleague I don't know very well asked me straight out "Why don't you have kids?". That was fairly rude. I've never asked anybody "Why do you have kids?". I thought it was intrusive but I just smiled and said "these things are always complex" and left it at that.
And my situation is complex. I don't feel I should have to explain any more. But at some point we made a choice not to do round after round of IVF so in that regard, we are a mix of childless by circumstance and childless by choice. But that's nobodies business.
My MIL and BIL are the worst though. They make me feel utterly worthless with their constant comments (I've just scratched the surface). My husband is quiet and was bullied growing up by his older brother so he never says anything... he's conflict averse so he'd never say anything more than "that's private".
I live in Ireland. I think it's still different to the UK and other countries. My generation of friends and certainly my parents generation see a woman's place in society as one reason and one reason only.