I don't get why everyone's so precious.
If you asked what I did, and I said I was a SAHM, I'd be pointing out I'm at home with the kids - Come over for coffee, invite us to the park, call me if you need a sitter for your doctor's appt.
I would in no way be insinuating that you didn't care enough to stay at home if you weren't.
If I had to describe myself and I said I was a Full Time Mum, I'd mean that I look after the kids every day - Again, come over for coffee, invite us out, etc.
I would certainly not be insinuating that you weren't if you worked.
If you asked and I said I was a WAHM, that's me telling you I work from home. It doesn't tell you whether my kids are there when I do, or not, so I wouldn't expect you to judge me, because I certainly wouldn't be judging you. I'm not using it to tell you that I prioritise school runs over a commute, or that you shouldn't expect a childminder to pick up your kids.
If I'm responding to a post online, and as part of my background information I happen at any point to mention the phrase "I'm lucky enough that I don't have to work", it means I am truly grateful that I do not have to work. It means that I'm free for coffee, park dates, as above. It does not mean that my life's better than yours, or my husband has a stellar job, or that we're minted. Just that I don't work, and that I don't want to brag, so I point out that I'm grateful.
Now, if anyone wants to ask such a personal question of someone they hardly know, and finds the respondent kind enough to offer one of the above instead of telling them to mind their own business?
Take it at face value. As a factual answer.
E.g Don't read into it, assign it any wistfulness you feel that you can't be with your kids because you need the money, project your guilt for choosing the career even though you don't need it, poke them with your jealousy stick, or otherwise insult their answer by assuming the worst about them.
You don't know if they chose it, or were forced into it, so you don't get to judge their choices or jump to the defensive.
They don't get to lord over you that they're in that position, and most times, they're won't.
Believe me, if they did, you'd know about it, and then you could take your ball, go home, and reserve the right not to make friends with them because they were being rude. And that's just fine.
But you don't get to assume that everyone who answers your question, or volunteers their information, has some sort of agenda to make people feel bad. Especially because tone of voice can't be read in text, most of the time.
For example, I typed this is a slightly sad, disappointed, low-volume 'voice' - but I bet a lot of people read it as a top-level rant in an angry, sarcastic, affronted tone. It's far too easy to project our own emotions onto someone else's words, which is a shame for communication all round.